This topic proposes low-power buffer means low quiescent current buffer amplifier. A dynamic floating current node is used at the output of two-stage amplifier to increase the charging and discharging of output capacitor as well as settling time of buffer. It is designed for 10 bit digital analog converter to support for LCD column driver it is implemented in 180 nm CMOS technology with the quiescent current of 5 μA for 30 pF capacitance, the settling time calculated as 4.5μs, the slew rate obtained as 5V/μs and area on chip is 30×72μ.
Comparators are basic building elements for designing modern analog and mixed signal systems. Speed and resolution are two important factors which are required for high speed applications. This paper presents a design for an on chip high-speed dynamic latched comparator for high frequency signal digitization. The dynamic latched comparator consists of two cross coupled inverters comprising a total of 9 MOS transistors. The measured and simulation results show that the dynamic latched comparator design has higher speed, low power dissipation and occupying less active area compared to double tail latched and preamplifier based clocked comparators. A new fully dynamic latched comparator which shows lower offset voltage and higher load drivability than the conventional dynamic latched comparators has been designed. With two additional inverters inserted between the input-stage and output-stage of the conventional double-tail dynamic comparator, the gain preceding the regenerative latch stage was improved and the complementary version of the output-latch stage, which has bigger output drive current capability at the same area, was implemented.
Analysis and design_of_a_low-voltage_low-power[1]Srinivas Naidu
The document presents an analysis of the delay characteristics of dynamic comparators. It analyzes the delay of conventional dynamic and double-tail comparators, deriving analytical expressions showing the impact of various design parameters on delay. A new dynamic comparator is then proposed based on modifying the circuit of a conventional double-tail comparator to strengthen positive feedback, reducing delay time. Simulation results on the proposed comparator show significantly reduced power consumption and delay compared to conventional designs, enabling higher clock frequencies at lower supply voltages.
Design of High-Speed Dynamic Double-Tail ComparatorIJERDJOURNAL
ABSTRACT:- The analog-to-digital converters which are of ultra low-power, area efficient, and high speed converters are made of dynamic regenerative comparators. These comparators can maximize speed and power efficiency. The delay and power dissipation of dynamic comparators are analyzed in this paper. The delays and tradeoff can be explored. The circuit of a conventional double tail comparator in this analysis is modified for fast operation even in different supply voltages. By using power gating technique and adding few transistors, the positive feedback during the regeneration is strengthened in the proposed comparator structure. The delay time can be reduced by providing positive feedback instead of adding few transistors. The analysis results are going to be confirmed on the basis of 0.25-µm CMOS technology. The power consumption and delay time can be significantly reduced based on this analysis. All the simulation are made using TANNER TOOLS, Generic 250nm. The schematic are drawn in the T-SPICE schematic editor.
Analysis and Design of A Low-Voltage Low-Power Double-Tail Comparator. This is a final semester Mtech project on VLSI design implementation of dual tail comparator in a modifyied version. This design is implemented using VHDL Language with 100% Source code synthesizable available. Software for free to download and knowledge transfer for the same project is also being implemented..The design is implemented using FSM technology, low power is achieved in this project.area utilization is the major advantage in this project.Low power techniques such as Clock gating, power gating is implemented in this project.,ieee reference paper is used for the base.
Analysis and design of a low voltage and low power double tail comparatorUshaswini Chowdary
The document describes the design and analysis of a low-voltage, low-power double-tail comparator. It begins by introducing comparators and their use in analog-to-digital converters. It then discusses challenges in designing high-speed comparators for modern low-voltage CMOS processes. The document analyzes delay in dynamic comparators and presents a new double-tail comparator design that aims to reduce latch delay time without requiring a boosted voltage. It describes the operation of conventional dynamic and double-tail comparators before detailing the proposed comparator's design which uses added control transistors to increase the initial differential output voltage and speed up latch regeneration.
An improved design of CMOS dynamic latch comparator with dual input dual output with a simple
design of three stages is represented. The basic disadvantages of latch type comparators are overcome by
producing an edge triggered comparison. The circuit is designed for a resolution of 300nV and the power
consumption is reduced to 450uW. It is designed for 1.8V DC supply voltage and 1 MHz clock frequency for
PVT variations. The simulation of the comparator is done in Cadence® Virtuoso Analog Design Environment
using 180nm technology. The error quotient is reduced less than 5% by adding a buffer stage. The delay is
brought down to 5nS. The active area appreciably is reduced. Layout of the proposed comparator has been
simulated in Cadence® Virtuoso Layout XL Design Environment. DRC and LVS have been verified.
Performance analysis of High Speed ADC using SR F/FIOSR Journals
This document analyzes the performance of a high-speed analog-to-digital converter (ADC) using a sense amplifier flip-flop (SAFF). It describes the design of a double tail current sense amplifier-based comparator combined with a symmetric set-reset (SR) latch. This design offers faster response and more stable output compared to conventional designs. Simulation results in 180nm and 90nm show the proposed SAFF has lower delay between outputs and lower power dissipation. Specifically, the delay between outputs is 0.029ns in 180nm and 0.011ns in 90nm for the proposed design, providing faster and more stable operation for high-speed ADCs compared to traditional comparator and latch designs.
2 twofold mode series echoing dc dc converter for ample loadchelliah paramasivan
The document describes a dual-mode full-bridge series resonant DC-DC converter that can operate at either a variable switching frequency or a fixed switching frequency with phase-shifted pulse width modulation to regulate the output voltage over a wide range of loads. The converter uses a series resonant tank consisting of an inductor and capacitor to achieve soft switching and zero voltage switching of the transistors. It can operate in a frequency modulation mode at high loads by varying the switching frequency, or in a phase modulation mode at light loads using a fixed high switching frequency and varying the duty cycle through phase-shifted pulse width modulation. This dual-mode operation provides high conversion efficiency across a wide range of loads.
Comparators are basic building elements for designing modern analog and mixed signal systems. Speed and resolution are two important factors which are required for high speed applications. This paper presents a design for an on chip high-speed dynamic latched comparator for high frequency signal digitization. The dynamic latched comparator consists of two cross coupled inverters comprising a total of 9 MOS transistors. The measured and simulation results show that the dynamic latched comparator design has higher speed, low power dissipation and occupying less active area compared to double tail latched and preamplifier based clocked comparators. A new fully dynamic latched comparator which shows lower offset voltage and higher load drivability than the conventional dynamic latched comparators has been designed. With two additional inverters inserted between the input-stage and output-stage of the conventional double-tail dynamic comparator, the gain preceding the regenerative latch stage was improved and the complementary version of the output-latch stage, which has bigger output drive current capability at the same area, was implemented.
Analysis and design_of_a_low-voltage_low-power[1]Srinivas Naidu
The document presents an analysis of the delay characteristics of dynamic comparators. It analyzes the delay of conventional dynamic and double-tail comparators, deriving analytical expressions showing the impact of various design parameters on delay. A new dynamic comparator is then proposed based on modifying the circuit of a conventional double-tail comparator to strengthen positive feedback, reducing delay time. Simulation results on the proposed comparator show significantly reduced power consumption and delay compared to conventional designs, enabling higher clock frequencies at lower supply voltages.
Design of High-Speed Dynamic Double-Tail ComparatorIJERDJOURNAL
ABSTRACT:- The analog-to-digital converters which are of ultra low-power, area efficient, and high speed converters are made of dynamic regenerative comparators. These comparators can maximize speed and power efficiency. The delay and power dissipation of dynamic comparators are analyzed in this paper. The delays and tradeoff can be explored. The circuit of a conventional double tail comparator in this analysis is modified for fast operation even in different supply voltages. By using power gating technique and adding few transistors, the positive feedback during the regeneration is strengthened in the proposed comparator structure. The delay time can be reduced by providing positive feedback instead of adding few transistors. The analysis results are going to be confirmed on the basis of 0.25-µm CMOS technology. The power consumption and delay time can be significantly reduced based on this analysis. All the simulation are made using TANNER TOOLS, Generic 250nm. The schematic are drawn in the T-SPICE schematic editor.
Analysis and Design of A Low-Voltage Low-Power Double-Tail Comparator. This is a final semester Mtech project on VLSI design implementation of dual tail comparator in a modifyied version. This design is implemented using VHDL Language with 100% Source code synthesizable available. Software for free to download and knowledge transfer for the same project is also being implemented..The design is implemented using FSM technology, low power is achieved in this project.area utilization is the major advantage in this project.Low power techniques such as Clock gating, power gating is implemented in this project.,ieee reference paper is used for the base.
Analysis and design of a low voltage and low power double tail comparatorUshaswini Chowdary
The document describes the design and analysis of a low-voltage, low-power double-tail comparator. It begins by introducing comparators and their use in analog-to-digital converters. It then discusses challenges in designing high-speed comparators for modern low-voltage CMOS processes. The document analyzes delay in dynamic comparators and presents a new double-tail comparator design that aims to reduce latch delay time without requiring a boosted voltage. It describes the operation of conventional dynamic and double-tail comparators before detailing the proposed comparator's design which uses added control transistors to increase the initial differential output voltage and speed up latch regeneration.
An improved design of CMOS dynamic latch comparator with dual input dual output with a simple
design of three stages is represented. The basic disadvantages of latch type comparators are overcome by
producing an edge triggered comparison. The circuit is designed for a resolution of 300nV and the power
consumption is reduced to 450uW. It is designed for 1.8V DC supply voltage and 1 MHz clock frequency for
PVT variations. The simulation of the comparator is done in Cadence® Virtuoso Analog Design Environment
using 180nm technology. The error quotient is reduced less than 5% by adding a buffer stage. The delay is
brought down to 5nS. The active area appreciably is reduced. Layout of the proposed comparator has been
simulated in Cadence® Virtuoso Layout XL Design Environment. DRC and LVS have been verified.
Performance analysis of High Speed ADC using SR F/FIOSR Journals
This document analyzes the performance of a high-speed analog-to-digital converter (ADC) using a sense amplifier flip-flop (SAFF). It describes the design of a double tail current sense amplifier-based comparator combined with a symmetric set-reset (SR) latch. This design offers faster response and more stable output compared to conventional designs. Simulation results in 180nm and 90nm show the proposed SAFF has lower delay between outputs and lower power dissipation. Specifically, the delay between outputs is 0.029ns in 180nm and 0.011ns in 90nm for the proposed design, providing faster and more stable operation for high-speed ADCs compared to traditional comparator and latch designs.
2 twofold mode series echoing dc dc converter for ample loadchelliah paramasivan
The document describes a dual-mode full-bridge series resonant DC-DC converter that can operate at either a variable switching frequency or a fixed switching frequency with phase-shifted pulse width modulation to regulate the output voltage over a wide range of loads. The converter uses a series resonant tank consisting of an inductor and capacitor to achieve soft switching and zero voltage switching of the transistors. It can operate in a frequency modulation mode at high loads by varying the switching frequency, or in a phase modulation mode at light loads using a fixed high switching frequency and varying the duty cycle through phase-shifted pulse width modulation. This dual-mode operation provides high conversion efficiency across a wide range of loads.
This document discusses resonant circuits and active filters. It begins by introducing the LC resonant circuit and defining its resonant frequency and quality factor. The transient response of a high-Q resonant circuit is then examined, showing that it will ring for many cycles if Q is large. Positive feedback techniques are explored, including a negative impedance circuit. Finally, various active filter circuit topologies are presented, including resonant circuits configured as filters and implementations using op-amps that replace inductors with capacitors and resistors.
This document discusses a dual mode series resonant DC-DC converter that can operate efficiently over a wide range of load variations. It presents a converter design that uses a full-bridge topology with series resonant components. The converter can operate in two modes - a switching frequency modulation mode for normal to high loads, and a phase shifted pulse width modulation mode for light loads. The dual mode operation allows for high conversion efficiency across the wide load range. Key aspects of the resonant converter design and operating principles are explained.
A 10-bit, 200MS/s CMOS Pipeline ADC using new shared opamp architecture VLSICS Design
A 10 bit opamp-sharing pipeline analog-to-digital converter (ADC) using a novel mirror telescopic operational amplifiers (opamp) with dual nmos differential inputs is presented. Reduction of power and area is achieved by completely merging the front-end sample-and-hold amplifier (SHA) into the first multiplying digital-to-analog converter (MDAC) using the proposed opamp. Transistors in the opamp are always biased in saturation to avoid increase of settling time due to opamp turn-on delays. The design targets 0.18um CMOS process for operation, at 200MS/s from a 1.8V supply. The simulation results show the SNDR and SFDR of 59.45dB and 68.69dB, respectively, and the power consumption of 35.04mW is achieved.
The document discusses power amplifiers and related concepts. It explains that power amplifiers have both a DC load line and an AC load line. The DC load line determines the quiescent operating point (Q point) while the AC load line determines the maximum output swing. For optimal performance without clipping, the Q point should be located at the center of the AC load line. The maximum unclipped peak-to-peak output is determined by either the product of collector current and AC resistance, or collector-emitter voltage - whichever is smaller. Proper biasing of the amplifier, including adjustment of the emitter resistance, can be used to position the Q point optimally on the AC load line.
CapSense Capacitive Sensors Sigma Delta AlgorithmRuth Moore
Cypress' CapSense Sigma-Delta algorithm (CSD) uses switched capacitor circuitry and analog/digital components to convert changes in capacitance from a sensor electrode into a digital bit stream. The bit stream is analyzed to determine if a conductive object is present by measuring the change in counts over measurement windows. CSD modulates the sensor capacitance using a switched capacitor network and comparator to create a variable duty cycle bit stream. This enables low power capacitive sensing for touch interfaces.
This document proposes and analyzes two new ultra low power CMOS transconductor circuit topologies called VLPT-gm and Delta-gm. These circuits operate transistors in the triode region to achieve very low transconductance values (gm) down to hundreds of pA/V, making them suitable for implementing gm-C filters with cutoff frequencies in the Hz and sub-Hz ranges. The document then describes how these new transconductors can be used as building blocks to realize a 6th-order wavelet filter for applications like medical sensors. Simulation results show the filters achieve transconductance tuning and total harmonic distortion below 1% while consuming only 51-114 nW of power from a 1.5V supply.
Stack Contention-alleviated Precharge Keeper for Pseudo Domino LogicjournalBEEI
The dynamic circuits are supposed to offer superior speed and low power dissipation over static CMOS circuits. The domino logic circuits are used for high system performance but suffer from the precharge pulse degradation. This article provides different design topologies on the domino circuits to overcome the charge sharing and charge leakage with reference to the power dissipation and delay. The precharge keeper circuit has been proposed such that the keeper transistors also work as the precharge transistors to realize multiple output function. The performance improvement of the circuit’s analysis have been done for adders and logic gates using HSPICE tool. The proposed keeper techniques reveal lower power dissipation and lesser delay over the standard keeper circuit with less transistor count for different process variation.
This document proposes a new passive power factor correction (PFC) circuit for flyback converters using an improved valley fill method. The circuit adds an extra winding magnetically coupled to the flyback transformer and electrically coupled to valley fill capacitors. This allows the capacitors to be charged through a high frequency inductor, reducing current spikes and total harmonic distortion. The proposed circuit provides PFC without an active switch, using low voltage capacitors at half the peak line voltage. Experimental results show the circuit achieves higher power factor and lower harmonic distortion than conventional valley fill methods.
IRJET - Wireless Power Transfer System using Pulse Density Modulation based F...IRJET Journal
This document summarizes a wireless power transfer system that uses a pulse density modulation based full bridge converter. The converter employs a zero-voltage switching technique to provide soft switching and improve efficiency. The existing pulse density modulation strategy for the converter has limitations like large low frequency subharmonics, a narrow modulation range, and large modulation delay. The document proposes a new pulse density modulation strategy that allows for asymmetric zero-voltage switching currents to overcome these limitations. Simulation results show the proposed strategy reduces subharmonics, achieves a wider modulation range, and faster response compared to the existing strategy.
The document summarizes the internship work of analyzing and modeling a DC/DC buck converter. Key points:
1) The intern designed a buck converter with a 5V load using a 20V source and an analog control system. Simulations were done in MATLAB.
2) Components like inductor, capacitor, controller gain were calculated. Simulation results showed the control system ensured a steady 5V output.
3) A circuit layout was designed but not realized due to lack of components. An Arduino-based approach was explored but not fully implemented.
4) The internship provided hands-on experience in power electronics design from modeling to implementation that will help in future academic pursuits.
This document describes several alternative dual-bridge matrix converter topologies that have a reduced number of switches compared to a conventional matrix converter. It discusses how the dual-bridge topology avoids commutation problems of the conventional design. It then introduces several dual-bridge topologies with fewer switches, including 18-, 15-, 12-, and 9-switch variations. It analyzes the characteristics and operation of these topologies, and presents simulation and experimental results for the 9-switch design to validate its feasibility.
A 80Ms/sec 10bit PIPELINED ADC Using 1.5Bit Stages And Built-in Digital Error...VLSICS Design
Use of pipelined ADCs is becoming increasingly popular both as stand alone parts and as embedded functional units in SOC design. They have acceptable resolution and high speed of operation and can be placed in relatively small area. The design is implemented in 0.18uM CMOS process. The design includes a folded cascode op-amp with a unity gain frequency of 200MHz at 88 deg. Phase margin and a dc gain of 75dB. The circuit employs a built in sample and hold circuit and a three phase non-overlapping clock.
Wide input range LLC resonant converters have drawbacks and limitations when used with a wide input voltage range from the mains. These include operating too close to the capacitive mode which can cause loss of zero voltage switching and reverse recovery of body diodes. It also results in a low attainable peak to nominal output power ratio or efficiency, especially at low loads. Other limitations include tighter tolerances required, lower duty cycle of the energy taking phase at low input voltages, and harder transformer design due to constraints. The presentation outlines these limitations and how to mitigate operating in the capacitive mode through frequency selection.
Minimum Mismatch of Current in Fully Differential Charge Pump for Integer N- ...IJERA Editor
Fully Differential ended charge pump (FDCP) are proven to have advantages over single ended charge pump at the cost of complexity and required more power for implementation for digital phase locked loop(DPLL). Wide swing cascodebias voltage with the rail to rail operational amplifier(opamp) as common mode feedback(CMFB) provides efficient solutions for current mismatch due to its non-idealities. The FDCP is simulated across process corners using 65nm technology with tsmc foundry for10Ghz DPLL. The power consumption of FDCP is 23mW with 100uA as Charge Pump (CP) current.
Design of an ADC using High Precision Comparator with Time Domain Offset Canc...IJTET Journal
Abstract— The comparator is a combinational logic circuit that plays an important role in the design of analog to digital converter. One of its most important properties is its input referred offset. When mismatches are present in a dynamic comparator, due to internal positive feedback and transient response, it is always challenging to analytically predict the input-referred random offset voltages since the operating points of transistors are time varying. To overcome the offset effect a novel time-domain bulk-tuned offset cancellation method is applied to a low power dynamic comparator. Using this comparator in analog to digital converter it does not increase the power consumption, but at the same time the delay is reduced and the speed is increased. The comparator is designed using the 250-nm CMOS technology in mentor graphics tool. Operating at a supply voltage of 5v and clock frequency 100MHZ, the comparator together with the offset cancellation circuitry dissipates 335.49nW of power and dissipates 1.027uW of power for comparator without offset cancellation circuit. The simulation result indicates that the offset cancellation circuitry consumes negligible power and it does not draw any static current. Using this high precision offset cancelled comparator in the analog to digital converter circuit the static power consumption is less and it is able to work under very low supply voltage.
This document summarizes an adaptive output stage Class D audio amplifier designed for high efficiency over a wide range of output powers. The design uses multiple output stages selected by a finite state machine to optimize efficiency based on the output power level. At low output powers, switching losses dominate, so a low-power stage is selected. At medium powers, both switching and conduction losses are significant, selecting a medium-power stage. At high powers, conduction losses dominate, selecting a high-power stage. A feed-forward technique is used to enhance power supply rejection. Simulation results show over 90% efficiency across output powers and a power supply rejection ratio of 69dB.
Iaetsd an mtcmos technique for optimizing lowIaetsd Iaetsd
The document proposes a new low-power flip-flop circuit called MT-CPSFF that uses multi-threshold CMOS (MTCMOS) technique. MTCMOS uses high-Vt sleep transistors to cut off power when in sleep mode, reducing leakage current. The MT-CPSFF combines MTCMOS with an existing low-power flip-flop called Clocked Pair Shared Flip-Flop (CPSFF) that shares clocked transistors. Simulation results show the MT-CPSFF consumes 66.3% less power than CPSFF. The document also analyzes other existing low-power flip-flop designs like CDFF, CDMFF and compares their power consumption to the
The effect of ripple steering on control loop stability for ac cm pfc boost c...Murray Edington
This document discusses the effect of ripple steering on control loop stability for continuous conduction mode (CCM) power factor correction (PFC) boost converters. It presents an average switch model approach to modeling the power stage, feedback compensation, and dynamics. Transfer functions are derived for a conventional boost converter and then a PFC boost converter with coupled magnetic filter. Experimental and simulation results from a 1.8 kW prototype verify the analytical work and model's ability to predict steady-state and dynamic behavior of CCM PFC boost converters with coupled magnetic filters. Ripple steering is shown to improve EMI filtering and reduce component sizes while allowing similar control strategies to conventional boost converters.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document discusses the implementation of a PI controller for a fourth order resonant power converter with a capacitive output filter. It begins by introducing the LCLC resonant converter topology, which employs more resonant elements and has desirable features for high voltage conversion. It then presents the mathematical model of the LCLC converter using state space equations. Finally, it discusses using a PI controller in a closed loop control scheme for the resonant converter to provide better voltage regulation under dynamic load conditions.
An operational amplifier with recycling folded cascode topology and adaptive ...VLSICS Design
This paper presents a highly adaptive operational amplifier with high gain, high bandwidth, high speed
and low power consumption. By adopting the recycling folded cascode topology along with an adaptivebiasing
circuit, this design achieves high performance in terms of gain-bandwidth product (GBW) and slew
rate (SR). This single stage op-amp has been designed in 0.18μm technology with a power supply of 1.8V
and a 5pF load. The simulation results show that the amplifier achieved a GBW of 335.5MHz, Unity Gain
Bandwidth of 247.1MHz and a slew rate of 92.8V/μs.
Vlsics040307DESIGN AND IMPLEMENTATION OF CAR PARKING SYSTEM ON FPGAVLSICS Design
As, the number of vehicles are increased day by day in rapid manner. It causes the problem of traffic
congestion, pollution (noise and air). To overcome this problem A FPGA based parking system has been
proposed. In this paper, parking system is implemented using Finite State Machine modelling. The system
has two main modules i.e. identification module and slot checking module. Identification module
identifies the visitor. Slot checking module checks the slot status. These modules are modelled in HDL
and implemented on FPGA. A prototype of parking system is designed with various interfaces like sensor
interfacing, stepper motor and LCD.
This document discusses resonant circuits and active filters. It begins by introducing the LC resonant circuit and defining its resonant frequency and quality factor. The transient response of a high-Q resonant circuit is then examined, showing that it will ring for many cycles if Q is large. Positive feedback techniques are explored, including a negative impedance circuit. Finally, various active filter circuit topologies are presented, including resonant circuits configured as filters and implementations using op-amps that replace inductors with capacitors and resistors.
This document discusses a dual mode series resonant DC-DC converter that can operate efficiently over a wide range of load variations. It presents a converter design that uses a full-bridge topology with series resonant components. The converter can operate in two modes - a switching frequency modulation mode for normal to high loads, and a phase shifted pulse width modulation mode for light loads. The dual mode operation allows for high conversion efficiency across the wide load range. Key aspects of the resonant converter design and operating principles are explained.
A 10-bit, 200MS/s CMOS Pipeline ADC using new shared opamp architecture VLSICS Design
A 10 bit opamp-sharing pipeline analog-to-digital converter (ADC) using a novel mirror telescopic operational amplifiers (opamp) with dual nmos differential inputs is presented. Reduction of power and area is achieved by completely merging the front-end sample-and-hold amplifier (SHA) into the first multiplying digital-to-analog converter (MDAC) using the proposed opamp. Transistors in the opamp are always biased in saturation to avoid increase of settling time due to opamp turn-on delays. The design targets 0.18um CMOS process for operation, at 200MS/s from a 1.8V supply. The simulation results show the SNDR and SFDR of 59.45dB and 68.69dB, respectively, and the power consumption of 35.04mW is achieved.
The document discusses power amplifiers and related concepts. It explains that power amplifiers have both a DC load line and an AC load line. The DC load line determines the quiescent operating point (Q point) while the AC load line determines the maximum output swing. For optimal performance without clipping, the Q point should be located at the center of the AC load line. The maximum unclipped peak-to-peak output is determined by either the product of collector current and AC resistance, or collector-emitter voltage - whichever is smaller. Proper biasing of the amplifier, including adjustment of the emitter resistance, can be used to position the Q point optimally on the AC load line.
CapSense Capacitive Sensors Sigma Delta AlgorithmRuth Moore
Cypress' CapSense Sigma-Delta algorithm (CSD) uses switched capacitor circuitry and analog/digital components to convert changes in capacitance from a sensor electrode into a digital bit stream. The bit stream is analyzed to determine if a conductive object is present by measuring the change in counts over measurement windows. CSD modulates the sensor capacitance using a switched capacitor network and comparator to create a variable duty cycle bit stream. This enables low power capacitive sensing for touch interfaces.
This document proposes and analyzes two new ultra low power CMOS transconductor circuit topologies called VLPT-gm and Delta-gm. These circuits operate transistors in the triode region to achieve very low transconductance values (gm) down to hundreds of pA/V, making them suitable for implementing gm-C filters with cutoff frequencies in the Hz and sub-Hz ranges. The document then describes how these new transconductors can be used as building blocks to realize a 6th-order wavelet filter for applications like medical sensors. Simulation results show the filters achieve transconductance tuning and total harmonic distortion below 1% while consuming only 51-114 nW of power from a 1.5V supply.
Stack Contention-alleviated Precharge Keeper for Pseudo Domino LogicjournalBEEI
The dynamic circuits are supposed to offer superior speed and low power dissipation over static CMOS circuits. The domino logic circuits are used for high system performance but suffer from the precharge pulse degradation. This article provides different design topologies on the domino circuits to overcome the charge sharing and charge leakage with reference to the power dissipation and delay. The precharge keeper circuit has been proposed such that the keeper transistors also work as the precharge transistors to realize multiple output function. The performance improvement of the circuit’s analysis have been done for adders and logic gates using HSPICE tool. The proposed keeper techniques reveal lower power dissipation and lesser delay over the standard keeper circuit with less transistor count for different process variation.
This document proposes a new passive power factor correction (PFC) circuit for flyback converters using an improved valley fill method. The circuit adds an extra winding magnetically coupled to the flyback transformer and electrically coupled to valley fill capacitors. This allows the capacitors to be charged through a high frequency inductor, reducing current spikes and total harmonic distortion. The proposed circuit provides PFC without an active switch, using low voltage capacitors at half the peak line voltage. Experimental results show the circuit achieves higher power factor and lower harmonic distortion than conventional valley fill methods.
IRJET - Wireless Power Transfer System using Pulse Density Modulation based F...IRJET Journal
This document summarizes a wireless power transfer system that uses a pulse density modulation based full bridge converter. The converter employs a zero-voltage switching technique to provide soft switching and improve efficiency. The existing pulse density modulation strategy for the converter has limitations like large low frequency subharmonics, a narrow modulation range, and large modulation delay. The document proposes a new pulse density modulation strategy that allows for asymmetric zero-voltage switching currents to overcome these limitations. Simulation results show the proposed strategy reduces subharmonics, achieves a wider modulation range, and faster response compared to the existing strategy.
The document summarizes the internship work of analyzing and modeling a DC/DC buck converter. Key points:
1) The intern designed a buck converter with a 5V load using a 20V source and an analog control system. Simulations were done in MATLAB.
2) Components like inductor, capacitor, controller gain were calculated. Simulation results showed the control system ensured a steady 5V output.
3) A circuit layout was designed but not realized due to lack of components. An Arduino-based approach was explored but not fully implemented.
4) The internship provided hands-on experience in power electronics design from modeling to implementation that will help in future academic pursuits.
This document describes several alternative dual-bridge matrix converter topologies that have a reduced number of switches compared to a conventional matrix converter. It discusses how the dual-bridge topology avoids commutation problems of the conventional design. It then introduces several dual-bridge topologies with fewer switches, including 18-, 15-, 12-, and 9-switch variations. It analyzes the characteristics and operation of these topologies, and presents simulation and experimental results for the 9-switch design to validate its feasibility.
A 80Ms/sec 10bit PIPELINED ADC Using 1.5Bit Stages And Built-in Digital Error...VLSICS Design
Use of pipelined ADCs is becoming increasingly popular both as stand alone parts and as embedded functional units in SOC design. They have acceptable resolution and high speed of operation and can be placed in relatively small area. The design is implemented in 0.18uM CMOS process. The design includes a folded cascode op-amp with a unity gain frequency of 200MHz at 88 deg. Phase margin and a dc gain of 75dB. The circuit employs a built in sample and hold circuit and a three phase non-overlapping clock.
Wide input range LLC resonant converters have drawbacks and limitations when used with a wide input voltage range from the mains. These include operating too close to the capacitive mode which can cause loss of zero voltage switching and reverse recovery of body diodes. It also results in a low attainable peak to nominal output power ratio or efficiency, especially at low loads. Other limitations include tighter tolerances required, lower duty cycle of the energy taking phase at low input voltages, and harder transformer design due to constraints. The presentation outlines these limitations and how to mitigate operating in the capacitive mode through frequency selection.
Minimum Mismatch of Current in Fully Differential Charge Pump for Integer N- ...IJERA Editor
Fully Differential ended charge pump (FDCP) are proven to have advantages over single ended charge pump at the cost of complexity and required more power for implementation for digital phase locked loop(DPLL). Wide swing cascodebias voltage with the rail to rail operational amplifier(opamp) as common mode feedback(CMFB) provides efficient solutions for current mismatch due to its non-idealities. The FDCP is simulated across process corners using 65nm technology with tsmc foundry for10Ghz DPLL. The power consumption of FDCP is 23mW with 100uA as Charge Pump (CP) current.
Design of an ADC using High Precision Comparator with Time Domain Offset Canc...IJTET Journal
Abstract— The comparator is a combinational logic circuit that plays an important role in the design of analog to digital converter. One of its most important properties is its input referred offset. When mismatches are present in a dynamic comparator, due to internal positive feedback and transient response, it is always challenging to analytically predict the input-referred random offset voltages since the operating points of transistors are time varying. To overcome the offset effect a novel time-domain bulk-tuned offset cancellation method is applied to a low power dynamic comparator. Using this comparator in analog to digital converter it does not increase the power consumption, but at the same time the delay is reduced and the speed is increased. The comparator is designed using the 250-nm CMOS technology in mentor graphics tool. Operating at a supply voltage of 5v and clock frequency 100MHZ, the comparator together with the offset cancellation circuitry dissipates 335.49nW of power and dissipates 1.027uW of power for comparator without offset cancellation circuit. The simulation result indicates that the offset cancellation circuitry consumes negligible power and it does not draw any static current. Using this high precision offset cancelled comparator in the analog to digital converter circuit the static power consumption is less and it is able to work under very low supply voltage.
This document summarizes an adaptive output stage Class D audio amplifier designed for high efficiency over a wide range of output powers. The design uses multiple output stages selected by a finite state machine to optimize efficiency based on the output power level. At low output powers, switching losses dominate, so a low-power stage is selected. At medium powers, both switching and conduction losses are significant, selecting a medium-power stage. At high powers, conduction losses dominate, selecting a high-power stage. A feed-forward technique is used to enhance power supply rejection. Simulation results show over 90% efficiency across output powers and a power supply rejection ratio of 69dB.
Iaetsd an mtcmos technique for optimizing lowIaetsd Iaetsd
The document proposes a new low-power flip-flop circuit called MT-CPSFF that uses multi-threshold CMOS (MTCMOS) technique. MTCMOS uses high-Vt sleep transistors to cut off power when in sleep mode, reducing leakage current. The MT-CPSFF combines MTCMOS with an existing low-power flip-flop called Clocked Pair Shared Flip-Flop (CPSFF) that shares clocked transistors. Simulation results show the MT-CPSFF consumes 66.3% less power than CPSFF. The document also analyzes other existing low-power flip-flop designs like CDFF, CDMFF and compares their power consumption to the
The effect of ripple steering on control loop stability for ac cm pfc boost c...Murray Edington
This document discusses the effect of ripple steering on control loop stability for continuous conduction mode (CCM) power factor correction (PFC) boost converters. It presents an average switch model approach to modeling the power stage, feedback compensation, and dynamics. Transfer functions are derived for a conventional boost converter and then a PFC boost converter with coupled magnetic filter. Experimental and simulation results from a 1.8 kW prototype verify the analytical work and model's ability to predict steady-state and dynamic behavior of CCM PFC boost converters with coupled magnetic filters. Ripple steering is shown to improve EMI filtering and reduce component sizes while allowing similar control strategies to conventional boost converters.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document discusses the implementation of a PI controller for a fourth order resonant power converter with a capacitive output filter. It begins by introducing the LCLC resonant converter topology, which employs more resonant elements and has desirable features for high voltage conversion. It then presents the mathematical model of the LCLC converter using state space equations. Finally, it discusses using a PI controller in a closed loop control scheme for the resonant converter to provide better voltage regulation under dynamic load conditions.
An operational amplifier with recycling folded cascode topology and adaptive ...VLSICS Design
This paper presents a highly adaptive operational amplifier with high gain, high bandwidth, high speed
and low power consumption. By adopting the recycling folded cascode topology along with an adaptivebiasing
circuit, this design achieves high performance in terms of gain-bandwidth product (GBW) and slew
rate (SR). This single stage op-amp has been designed in 0.18μm technology with a power supply of 1.8V
and a 5pF load. The simulation results show that the amplifier achieved a GBW of 335.5MHz, Unity Gain
Bandwidth of 247.1MHz and a slew rate of 92.8V/μs.
Vlsics040307DESIGN AND IMPLEMENTATION OF CAR PARKING SYSTEM ON FPGAVLSICS Design
As, the number of vehicles are increased day by day in rapid manner. It causes the problem of traffic
congestion, pollution (noise and air). To overcome this problem A FPGA based parking system has been
proposed. In this paper, parking system is implemented using Finite State Machine modelling. The system
has two main modules i.e. identification module and slot checking module. Identification module
identifies the visitor. Slot checking module checks the slot status. These modules are modelled in HDL
and implemented on FPGA. A prototype of parking system is designed with various interfaces like sensor
interfacing, stepper motor and LCD.
An efficient multi resolution filter bank based on da based multiplicationVLSICS Design
Multi-resolution filter bank (MRFB)-based on the fast filter bank design can be used for multiple resolution
spectrum sensing. MRFB overcomes the constraint of fixed sensing resolution in spectrum sensors based
on conventional discrete Fourier transform filter banks (DFTFB) without hardware re-implementation.
Multipliers have a greater impact on complexity and performance of the design because a large number of
constant multiplications are required in the multiplication of filter coefficients with the filter input.
Modified multiplier architecture Distributed Arithmetic(DA) is used to improve the efficiency
Tracking cancer patients medical history using wireless emerging technology ...VLSICS Design
The principal objective of this paper is to present an effective solution for storing and retrieving a cancer
patient’s medical history in hospitals, clinics and wherever else need be. We have used latest technologies like Near Field Communication (NFC) as a medium for communication, MySQL server for storing the database i.e. EHR (Electronic Health Record) of patients and lastly an Android application which will provide the interface for the same.
DESIGN OF PARITY PRESERVING LOGIC BASED FAULT TOLERANT REVERSIBLE ARITHMETIC ...VLSICS Design
Reversible Logic is gaining significant consideration as the potential logic design style for implementation
in modern nanotechnology and quantum computing with minimal impact on physical entropy .Fault
Tolerant reversible logic is one class of reversible logic that maintain the parity of the input and the
outputs. Significant contributions have been made in the literature towards the design of fault tolerant
reversible logic gate structures and arithmetic units, however, there are not many efforts directed towards
the design of fault tolerant reversible ALUs. Arithmetic Logic Unit (ALU) is the prime performing unit in
any computing device and it has to be made fault tolerant. In this paper we aim to design one such fault
tolerant reversible ALU that is constructed using parity preserving reversible logic gates. The designed
ALU can generate up to seven Arithmetic operations and four logical operations.
ANALYSIS OF SMALL-SIGNAL PARAMETERS OF 2-D MODFET WITH POLARIZATION EFFECTS F...VLSICS Design
An improved analytical two dimensional (2-D) model for AlGaN/GaN modulation doped field effect
transistor (MODFET) has been developed. The model is based on the solution of 2-D Poisson’s equation.
The model includes the spontaneous and piezoelectric polarization effects. The effects of field dependent
mobility, velocity saturation and parasitic resistances are included in the current voltage characteristics of
the developed two dimensional electron gas (2-DEG) model. The small-signal microwave parameters have
been evaluated to determine the output characteristics, device transconductance and cut-off frequency for
50 nm gate length. The peak transconductance of 165mS/mm and a cut-off frequency of 120 GHz have been
obtained. The results so obtained are in close agreement with experimental data, thereby proving the
validity of the model.
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Design of a novel current balanced voltage controlled delay elementVLSICS Design
This paper presents a design of fast voltage controlled delay element based on modified version of low
noise Current Balanced Logic (CBL). This delay element provides identical rising and falling edge delays
controlled by the single control voltage. The post layout tunable delay range is from 140 ps to 800 ps over
control voltage range of 0 to 2.1 V. An analysis for the delay element is also presented, which is in
agreement with the simulated delays. A Delay Lock Loop (DLL) is designed using this delay element to
verify its performance.
EVALUATION OF OPTICALLY ILLUMINATED MOSFET CHARACTERISTICS BY TCAD SIMULATIONVLSICS Design
In this paper we report effect of optical illumination on Silicon MOSFET. The MOSFET has been studied in
respect of current voltage, transconductance admittance and scattering parameters. Gain analysis of the
Silicon MOSFET is done in dark and under optical illumination. The device is fabricated using ATHENA™
process simulator and the device simulation is performed using ATLAS™ from SILVACO international.
The simulation results indicate potential of MOSFET as optically sensitive structure which can be used
for increase in data transmission/reception rates, reduction of interconnect delays, elimination of clock
skew, or as a photodetector for optoelectronic applications at low and radio frequency.
A DAPTIVE S UPPLY V OLTAGE M ANAGEMENT F OR L OW P OWER L OGIC C IRCU...VLSICS Design
With the rise in demand of portable hand held devic
es and with the rise in application of wireless sen
sor
networks and RFID reduction of total power consumpt
ion has become a necessity. To save power we
operate the logic circuitry of our devices at sub-t
hreshold. In sub-threshold the drain current is
exponentially dependent on the threshold voltage he
nce the threshold variation causes profound variati
on
of I
ON
and I
OFF
the ratio of which affect the speed of a circuit d
rastically. So to mitigate this problem we
present a adaptive power management circuit which w
ill determine the minimum required supply voltage
to meet the timing requirement. Also to reduce the
power overhead and avoid bulky coil and EMI noise
we used the switch capacitor power regulator to reg
ulate and manage power instead of linear dropout
(LDO) and Inductor base switch mode power converter
ANALOG MODELING OF RECURSIVE ESTIMATOR DESIGN WITH FILTER DESIGN MODELVLSICS Design
This document summarizes a research paper on implementing a low power design methodology for recursive encoders and decoders. It discusses how recursive coding can achieve better error correction performance at low signal-to-noise ratios compared to other codes. It then describes the design of a recursive decoder that uses the log-MAP algorithm to minimize power consumption. The decoder uses five main computational steps - branch metric calculation, forward metric computation, backward metric computation, log-likelihood ratio calculation, and extrinsic information calculation. It also compares the implementation of four-state and eight-state recursive encoders. The goal of the design is to optimize the power and area of recursive encoders and decoders.
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A NEW LOW VOLTAGE P-MOS BULK DRIVEN CURRENT MIRROR CIRCUITVLSICS Design
This document summarizes a research paper that proposes a new low voltage current mirror circuit using a bulk-driven technique. The proposed circuit consists of 4 PMOS and 5 NMOS transistors and can operate at a supply voltage of +0.85V. It uses bulk connections to reduce the threshold voltage of the PMOS transistors. The document describes the circuit operation and provides its AC equivalent model. It was simulated in Cadence using a 180nm process and was found to function as a current mirror.
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DESIGN AND PERFORMANCE ANALYSIS OF ZBT SRAM CONTROLLERVLSICS Design
Memory is an essential part of electronic industry. Since, the processors used in various high performance
PCs, network applications and communication equipment require high speed memories. The type of
memory used depends on system architecture, and its applications. This paper presents an SRAM
architecture known as Zero Bus Turnaround (ZBT). This ZBT SRAM is mainly developed for networking
applications where frequent READ/WRITE transitions are required. The other single data rate SRAMs are
inefficient as they require idle cycles when they frequently switch between reading and writing to the
memory. This controller is simulated on the Spartan 3 device. And the performance analysis is done on the
basis of area, speed and power.
Energy Efficient Full Adder Cell Design with Using Carbon Nanotube Field Effe...VLSICS Design
This document summarizes a research paper that proposes a new low-power full adder cell design using carbon nanotube field-effect transistors (CNTFETs) in 32 nanometer technology. Simulation results show that the design, which uses 24 CNTFETs, reduces power consumption compared to previous CNTFET full adder designs. The power and power-delay product increase with supply voltage but are largely unaffected by temperature. Compared to previous designs, the proposed cell has lower power, delay, and power-delay product, especially at 0.65V supply voltage, demonstrating its improved energy efficiency.
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Compact low power high slew-rate cmos buffer amplifier with power gating tech...VLSICS Design
A qualitative analysis of different parameters such as Phase noise, Slew rate and tranconductance by using
power gating reduction technique is presented. The circuit achieves the large driving capability by
employing simple comparators to sense the transients of the input to turn on the output stages, which are
statically off in the stable state. The effect of the different number of transistors and their topologies on the
phase noise and Slew rate is analyzed. Good agreement between qualitative and quantitative measurements
is observed. Scope of reducing of Noise and avoidance of Leakage due to various sources is discussed.
Design of Low Voltage Low Power CMOS OP-AMPIJERA Editor
Operational amplifiers are an integral part of many analog and mixed signal systems. As the demand for mixed
mode integrated circuits increases, the design of analog circuits such as operational amplifiers in CMOS
technology becomes more critical. This paper presents a two stage CMOS operational amplifier, which operates
at ±1.8V power supply using TSMC 0.18um CMOS technology. The OP-AMP designed exhibit unity gain
frequency of 12.6 MHz, and gain of 55.5db with 300uw power dissipation. The gain margin and phase margin
of OP-AMP is 45˚ and 60˚ respectively. Design and simulation has been carried out in P Spice tool.
Physical designing of low power operational amplifierDevendra Kushwaha
The document provides details about a master's thesis project to design a novel low power operational amplifier. It begins with an introduction to operational amplifiers, describing their basic structure and ideal characteristics. The literature review discusses previous work on designing low power and low noise operational amplifiers using techniques like current driven bulk, Miller compensation, and class AB amplifiers. Key inferences from the literature are that most work has been done on 120nm CMOS technology, noise can be reduced by adjusting transconductance, and cascoded structures provide better gain than cascaded structures. The document outlines the scope of work, methodology, expected outcomes, and software requirements for the thesis project.
A Low Noise Two Stage Operational Amplifier on 45nm CMOS ProcessIRJET Journal
This document describes the design and simulation of a low noise, two stage operational amplifier implemented in 45nm CMOS technology. A two stage op-amp circuit is presented with a differential amplifier as the first stage and a common source amplifier as the second stage. Miller capacitance compensation is used to achieve stability. Simulations show the op-amp achieves a gain of 6.1dB, output voltage of 0.92V, spurious free dynamic range of 8dB at 20MHz, and slew rate of 62.8V/μs with a 1.2V power supply. The op-amp demonstrates good performance for low noise and power applications using 45nm CMOS technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
IRJET-Design of Capacitor Less LDO Regulator by using Cascode Compensation Te...IRJET Journal
The document discusses two approaches to designing low dropout voltage regulators (LDOs). The first approach uses a basic LDO design with a compensation capacitor to achieve stability. This design has a dropout voltage of 200mV and provides an output voltage of 1.4V with a bandwidth of 475.67 KHz and phase margin of 43.85 degrees. The second approach aims to design a capacitor-less LDO using cascode compensation technique. This design achieves a lower dropout voltage of 100mV and higher bandwidth of 2.55 MHz and phase margin of 63 degrees through the use of an 80pF miller compensation capacitor and 50 kOhm series resistor to shift the right half plane zero and improve stability without requiring an
This document analyzes the dynamic response of a power factor correction (PFC) converter. It discusses how the bandwidth of the compensator in the output voltage feedback loop affects the transient response. Specifically, it notes that a wider bandwidth improves response but introduces more voltage ripple, while a narrow bandwidth has slower response but less ripple. The document presents modeling of the converter with different levels of voltage ripple and analyzes how it impacts the static behavior and harmonic distortion. Simulation results demonstrate the tradeoff between response, ripple and power quality for low-bandwidth versus high-bandwidth designs.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A RAIL-TO-RAIL HIGH SPEED CLASS-AB CMOS BUFFER WITH LOW POWER AND ENHANCED SL...VLSICS Design
This document summarizes a research paper that proposes a new rail-to-rail class-AB CMOS buffer circuit designed to drive large capacitive loads at high speed with low power dissipation. The proposed circuit uses a new leakage current reduction technique called LECTOR that adds leakage control transistors to reduce sub-threshold leakage current. Simulation results show the circuit operates at 3V with a propagation delay of 292.1×10-12 seconds and leakage current of 118.4μA, representing improvements over prior designs. The settling time is also improved to 41.12×10-9 seconds. In conclusion, the proposed buffer circuit achieves both high speed and low power operation suitable for driving large capacitive loads.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A 80Ms/sec 10bit PIPELINED ADC Using 1.5Bit Stages And Built-in Digital Error...VLSICS Design
Use of pipelined ADCs is becoming increasingly popular both as stand alone parts and as embedded functional units in SOC design. They have acceptable resolution and high speed of operation and can be placed in relatively small area. The design is implemented in 0.18uM CMOS process. The design includes a folded cascode op-amp with a unity gain frequency of 200MHz at 88 deg. Phase margin and a dc gain of 75dB. The circuit employs a built in sample and hold circuit and a three phase non-overlapping clock.
IRJET-Design of Charge Pump for PLL with Reduction In Current Mismatch and Va...IRJET Journal
The document describes the design of an improved charge pump circuit for phase locked loops (PLLs) with reduced current mismatch and variation. A current steering topology is used along with a feedback loop and compensation circuit. The proposed charge pump was designed in 180nm CMOS technology and simulated using Cadence. It achieved a current mismatch between 10-21%, flat output current over a 0.514V output voltage variation, and an output voltage swing of 1.525V. This represents an improvement over conventional charge pump designs in terms reducing current variation and extending the output voltage range.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A High-Speed, Low Power Consumption Positive Edge Triggered D Flip-Flop for H...VLSICS Design
A high speed low power consumption positive edge triggered Delayed (D) flip-flop was designed for increasing the speed of counter in Phase locked loop, using 180 nm CMOS technology. The designed counter has been used in the divider chip of the phase locked loop. A divide counter is required in the feedback loop to increase the VCO frequency above the input reference frequency. The proposed circuit is faster than conventional circuit as it has fast reset operation. The circuit consumes less power as it prevents short circuit power consumption. The circuit operates at 1.8V power supply. This work has been used in the design. of 2.4 GHz CMOS PLL targeting OFDM application. The CMOS based fast D-ff circuit has designed and simulated by Virtuoso tool of CADENCE spectre
International Journal of Engineering and Science Research. It is a international journal publishing high-quality articles dedicated to all aspects of engineering. IJESR is to publish peer reviewed research and review articles. fastly without delay in the developing field of engineering and science Research.
HARMONIC MITIGATION USING D STATCOM THROUGH A CURRENT CONTROL TECHNIQUEJournal For Research
The harmonic mitigation using shunt active filters are most widely used in industrial and commercial applications. In this paper a Multi-Level Inverter is considered as DSTATCOM to compensate harmonics. The mathematical modeling of the system and design of the controller using synchronous reference frame theory is also presented. The nonlinear load generally known as diode rectifier load and an unbalanced load is simulated with the system using MATLAB/SIMULINK.
A High-Swing OTA with wide Linearity for design of self-tunable linear resistorVLSICS Design
Low power consumption, long battery life and portability are essential requirements of modern health monitoring products. Operational Transconductance Amplifier (OTA) operating in subthreshold region is an basic building block for low power health monitoring products design. An modified design of OTA which incorporates better linearity and increased output impedance has been discussed in this paper. The proposed OTA uses High-swing improved-Wilson current mirror for low power and low-frequency applications. The achieved linearity is about ± 1.9 volt and unity gain bandwidth (UGB) of 342.30 KHz at power supply of 0.9 volt which makes OTA to consume power in range of nanowatts. The proposed low voltage OTA implementation in design of self- tunable linear resistor has been presented in this paper. The circuit implementation has been done using standard 0.18 micron technology provided by TSMC on BSIM 3v3 level-53 model parameter and verified results through use of ELDO Simulator.
This document describes a technique for improving the efficiency of charge pump circuits used in low-voltage applications such as RFID and sensor networks. It proposes using a threshold voltage cancellation technique to completely turn on and off MOSFET switches in the charge pump. An enhanced gate boosting technique is then added to further improve efficiency by overdriving switches in the on state and underdriving them in the off state. Simulation results show the improved charge pump provides higher output voltages and pumping efficiency compared to a standard Dickson charge pump, especially at low supply voltages.
Similar to Dynamic floating output stage for low power buffer amplifier for lcd application (20)
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/temporal-event-neural-networks-a-more-efficient-alternative-to-the-transformer-a-presentation-from-brainchip/
Chris Jones, Director of Product Management at BrainChip , presents the “Temporal Event Neural Networks: A More Efficient Alternative to the Transformer” tutorial at the May 2024 Embedded Vision Summit.
The expansion of AI services necessitates enhanced computational capabilities on edge devices. Temporal Event Neural Networks (TENNs), developed by BrainChip, represent a novel and highly efficient state-space network. TENNs demonstrate exceptional proficiency in handling multi-dimensional streaming data, facilitating advancements in object detection, action recognition, speech enhancement and language model/sequence generation. Through the utilization of polynomial-based continuous convolutions, TENNs streamline models, expedite training processes and significantly diminish memory requirements, achieving notable reductions of up to 50x in parameters and 5,000x in energy consumption compared to prevailing methodologies like transformers.
Integration with BrainChip’s Akida neuromorphic hardware IP further enhances TENNs’ capabilities, enabling the realization of highly capable, portable and passively cooled edge devices. This presentation delves into the technical innovations underlying TENNs, presents real-world benchmarks, and elucidates how this cutting-edge approach is positioned to revolutionize edge AI across diverse applications.
Skybuffer AI: Advanced Conversational and Generative AI Solution on SAP Busin...Tatiana Kojar
Skybuffer AI, built on the robust SAP Business Technology Platform (SAP BTP), is the latest and most advanced version of our AI development, reaffirming our commitment to delivering top-tier AI solutions. Skybuffer AI harnesses all the innovative capabilities of the SAP BTP in the AI domain, from Conversational AI to cutting-edge Generative AI and Retrieval-Augmented Generation (RAG). It also helps SAP customers safeguard their investments into SAP Conversational AI and ensure a seamless, one-click transition to SAP Business AI.
With Skybuffer AI, various AI models can be integrated into a single communication channel such as Microsoft Teams. This integration empowers business users with insights drawn from SAP backend systems, enterprise documents, and the expansive knowledge of Generative AI. And the best part of it is that it is all managed through our intuitive no-code Action Server interface, requiring no extensive coding knowledge and making the advanced AI accessible to more users.
Introduction of Cybersecurity with OSS at Code Europe 2024Hiroshi SHIBATA
I develop the Ruby programming language, RubyGems, and Bundler, which are package managers for Ruby. Today, I will introduce how to enhance the security of your application using open-source software (OSS) examples from Ruby and RubyGems.
The first topic is CVE (Common Vulnerabilities and Exposures). I have published CVEs many times. But what exactly is a CVE? I'll provide a basic understanding of CVEs and explain how to detect and handle vulnerabilities in OSS.
Next, let's discuss package managers. Package managers play a critical role in the OSS ecosystem. I'll explain how to manage library dependencies in your application.
I'll share insights into how the Ruby and RubyGems core team works to keep our ecosystem safe. By the end of this talk, you'll have a better understanding of how to safeguard your code.
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
Generating privacy-protected synthetic data using Secludy and MilvusZilliz
During this demo, the founders of Secludy will demonstrate how their system utilizes Milvus to store and manipulate embeddings for generating privacy-protected synthetic data. Their approach not only maintains the confidentiality of the original data but also enhances the utility and scalability of LLMs under privacy constraints. Attendees, including machine learning engineers, data scientists, and data managers, will witness first-hand how Secludy's integration with Milvus empowers organizations to harness the power of LLMs securely and efficiently.
5th LF Energy Power Grid Model Meet-up SlidesDanBrown980551
5th Power Grid Model Meet-up
It is with great pleasure that we extend to you an invitation to the 5th Power Grid Model Meet-up, scheduled for 6th June 2024. This event will adopt a hybrid format, allowing participants to join us either through an online Mircosoft Teams session or in person at TU/e located at Den Dolech 2, Eindhoven, Netherlands. The meet-up will be hosted by Eindhoven University of Technology (TU/e), a research university specializing in engineering science & technology.
Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
Power Grid Model is an open source project from Linux Foundation Energy and provides a calculation engine that is increasingly essential for DSOs. It offers a standards-based foundation enabling real-time power systems analysis, simulations of electrical power grids, and sophisticated what-if analysis. In addition, it enables in-depth studies and analysis of the electrical power grid’s behavior and performance. This comprehensive model incorporates essential factors such as power generation capacity, electrical losses, voltage levels, power flows, and system stability.
Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
For the upcoming meetup we are organizing, we have an exciting lineup of activities planned:
-Insightful presentations covering two practical applications of the Power Grid Model.
-An update on the latest advancements in Power Grid -Model technology during the first and second quarters of 2024.
-An interactive brainstorming session to discuss and propose new feature requests.
-An opportunity to connect with fellow Power Grid Model enthusiasts and users.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
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Dynamic floating output stage for low power buffer amplifier for lcd application
1. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
DOI : 10.5121/vlsic.2015.6102 9
DYNAMIC FLOATING OUTPUT STAGE FOR
LOW POWER BUFFER AMPLIFIER FOR LCD
APPLICATION
Hari shanker srivastava and Dr.R.K Baghel
Department of Electronics and Communication
MANIT Bhopal
ABSTRACT
This topic proposes low-power buffer means low quiescent current buffer amplifier. A dynamic floating
current node is used at the output of two-stage amplifier to increase the charging and discharging of
output capacitor as well as settling time of buffer. It is designed for 10 bit digital analog converter to
support for LCD column driver it is implemented in 180 nm CMOS technology with the quiescent current
of 5 µA for 30 pF capacitance, the settling time calculated as 4.5µs, the slew rate obtained as 5V/µs and
area on chip is 30×72µ݉ଶ
.
KEYWORDS
Liquid crystal display (LCD) ,column driver, row driver, gamma correction, class AB output stage
1. INTRODUCTION
With increasing demand of low-power portable LCD panel there was hard-core research to
develop it as with the low-power means we have to decrease the static loss of the component or
the blocks used in the driving scheme of the LCD panel, the driving scheme of LCD panel is
shown in figure 1, which consists of source driver circuits (column driver), gate driver
circuits(row driver), the reference voltages, timing controller's, gamma correction circuits,
column driver is used to drive a pixel with required colored information and row driver used to
refresh a pixel which required refreshing rate.[1,2] The column driver as shown in fig.2 contains
input registers, shift registers, level shifters, digital to analog converter and buffer amplifiers. The
column driver which is important to achieve the high resolution, high-speed, and low power
dissipation among these output buffers is the key to determine the speed, resolution, and power
consumption each pixel is derived by a buffer amplifier which is either positive polarity or
negative polarity to drive the alternate pixel.
2. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
10
Fig 1.Block diagram of LCD panel
Fig 2.Column driver architecture of LCD
3. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
11
Fig 3.Architecture of an R_DAC based column
Fig 4. Dot inversion method to drive
There are four driving schemes for LCD panels these are row inversion, column inversion, frame
inversion and dot inversion method, dot inversion method is best to drive a particular pixel to
remove cross talk figure.4 shows its driving scheme adjacent pixel is driven by either a positive
polarity buffer or by negative polarity buffer with due respect to common voltage, this will
improve the lifetime of the liquid crystal.[3],[4],[5].The figure.4 shows a driving method of
column driver to drive a pixel each adjacent pixels are driven by positive and negative polarity
buffer [8-11].
In proposed buffer amplifier a single buffer which contain NMOS & PMOS differential pair,
PMOS buffer has large discharge capability and NMOS has large charge capability are used to
drive the adjacent pixel to follow the dot inversion technique. A floating output stage is used to
control the biasing current of output stage using aspect ratio of MOS used in output stage.
2. FREQUENCY ANALYSIS OF TWO STAGE BUFFER
To drive high capacitive and resistive load of the pixel a class AB output stage is best suited for
the column driver line. For low offset voltage we need high open loop gain of buffer amplifier,
two-stage amplifier are generally used to drive the pixel, amplifier requires compensation
capacitor for the stability as the phase margin of the operation amplifier depend upon the
compensation capacitor, the slew rate is also depends on compensation capacitor. As some
buffers adopt output node to get the stability without using Miller capacitance, some uses charge
4. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
12
conservation technique to reduce the dynamic power loss without Miller capacitance. These
buffer suffers from charge storage problem as during scanning off time of row driver's the
columns lines are for a small duration of time is isolated from the pixels to refresh formation at
buffer quickly, so we need a capacitor which is fulfilled by compensation capacitor so those
buffers which are without compensation capacitors have a problem that they can't refresh there
information within the refresh time. As the proposed buffer has two-stage with the Miller
capacitor for the compensation is used in design. The figures.5 shows the equivalent circuit of
two stage operational amplifier with output load resistance and capacitance.
ࡾࡸ
ࡸ
Fig 5. Small signal model of proposed buffer amplifier
Figure 5 shows small signal equivalent diagram of proposed amplifier for two stage under open
loop, ݃ଵ & ݃ଶ are the transconductance, ܴଵ & ܴଶ are the output resistance, ܥଵ & ܥଶ are the
open loop parasitic capacitance of the first and second stages, ܥ is the miller capacitance for
phase compensation and ܴ& ܥare the resistive and capacitive load.
The transfer function of the amplifier is calculated using current equation:-
using current equation at input node:
݃ଵܸௗ +
ܸଵ
ܴଵ
+ ܵܥଵܸଵ + ሺܸଵ − ܸሻܵܥ = 0
ܸଵ ቂ
ଵ
ோభ
+ ܵሺܥଵ + ܥሻቃ = ܸܵܥ − ݃ଵܸௗ (1)
using current equation at output node:
݃ଶܸଵ +
ܸ
ܴଶ
+ ܵܥଶܸ + ሺܸ − ܸଵሻܵܥ +
ܸ
ቀܴ +
1
ܵܥ
ቁ
= 0
ܸ
1
ܴଶ
+ ܵሺܥଵ + ܥሻ +
ܵܥ
1 + ܴܵܥ
൨ = ܸଵሺܵܥ − ݃ଶሻ ሺ2ሻ
Put value of ܸଵfrom equation 1 to equation 2 we get,
5. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
13
ܸ
ܸௗ
=
݃ଵ݃ଶܴଵܴଶ ൬1 −
ܵܥ
݃ଶ
൰ሺ1 + ܴܵܥሻ
1 + ܣଵܵ + ܣଶܵଶ + ܣଷܵଷ
ሺ3ሻ
ܣଵ = ܴଵሺܥଵ + ܥሻ + ܴܥ + ܴଶሺܥଶ + ܥሻ + ܥܴଶ + ܴଵܴଶ݃ଶܥ
ܣଶ = ܴଵܴܥሺܥଵ + ܥሻ + ܴଵܴଶሺܥଵ + ܥሻሺܥଶ + ܥሻ + ܴଵܴଶܥሺܥଵ + ܥሻ + ܥܴܴଶሺܥଶ + ܥሻ
+ ܴଵܴଶܥሾܥ − ሺܥଵ + ܥሻ݃ଶܴଵሿ
ܣଷ = ܴଵܴଶܴܥሺܥଵ + ܥሻሺܥଶ + ܥሻ + ܴଵ
ଶ
ܴଶܥ
ଶ
ሺܥଵ + ܥሻ
As from equation 3 it show 3rd order transfer function
ܣሺܵሻ =
ܣௗ ቀ1 +
ܵ
߱ଵ
ቁ ቀ1 +
ܵ
߱ଶ
ቁ
ቀ1 +
ܵ
߱ଵ
ቁ ቀ1 +
ܵ
߱ଶ
ቁ ቀ1 +
ܵ
߱ଷ
ቁ
to solve the 3rd order transfer function using dominant pole concept, the characteristic equation is
written as:
1 + ܣଵܵ + ܣଶܵଶ
+ ܣଷܵଷ
= 0
≈ ܣଵܵ + ܣଶܵଶ
+ ܣଷܵଷ
= 0
≈ ܣଵܵሺ1 +
ܣଶ
ܣଵ
ܵ +
ܣଷ
ܣଵ
ܵଶ
ሻ = 0
߱ଵ ≅ −
1
ܣଵ
߱ଶ ≅
ܣଵ
ܣଶ
߱ଷ =
1
ܲଶ
ܣଵ
ܣଶ
ܣௗ = ݃ଵ݃ଶܴଵܴଶ
߱ଵ ≅
1
ܴଵܴଶ݃ଶܥ + ܥܴଶ
߱ଶ ≅
1
ሾሺܥଵ + ܥሻܴሿ
6. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
14
߱ଷ ≅
݃ଶܥ +
ܥ
ܴଵ
ൗ
ܥܥ
߱ଵ =
ିమ
and ߱ଶ =
ଵ
ோಽಽ
the unity gain frequency(߱௧)= ܣௗ ߱ଵ
߱௧ =
݃ଵ݃ଶ
ܥ݃ଶ +
ܥ
ܴଵ
ൗ
taking 3rd pole very far away from unity gain bandwidth so it does not affect the phase margin
so ߱ଶ will compensate for ߱ଷ so the transfer function act like 2nd order transfer function,
ܣሺܵሻ =
ܣௗ ቀ1 +
ܵ
߱′ଵ
ቁ
ቀ1 +
ܵ
߱′ଵ
ቁ ቀ1 +
ܵ
߱′ଶ
ቁ
where ߱′ଵ =
ିమ
߱′ଵ ≅
1
ܴଵܴଶ݃ଶܥ
߱ଶ ≅
݃ଶ
ሾܥଶሿ
Phase margin of the amplifier is as:
< ܣሺܵሻ = ݊ܽݐିଵ
൬
߱
߱′ଵ
൰ − ݊ܽݐିଵ
൬
߱
߱′ଵ
൰ − ݊ܽݐିଵ
൬
߱
߱′ଶ
൰
as ω=GBW(taken this as a frequency range)
< ܣሺܵሻ = −݊ܽݐିଵ
൬
GBW
߱′ଵ
൰ − ݊ܽݐିଵ
൬
GBW
߱′ଵ
൰ − ݊ܽݐିଵ
൬
GBW
߱′ଶ
൰
under condition ߱′ଵ ≥ 10ܹܤܩ
< ܣሺܵሻ = ݊ܽݐିଵ
൬
GBW
߱′ଵ
൰ − ݊ܽݐିଵሺܣௗ ሻ − ݊ܽݐିଵ
൬
GBW
߱′ଶ
൰
as ܣௗ is very higher value so ݊ܽݐିଵሺܣௗ ሻ=90
7. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
15
< −180
− ܲܯ = ݊ܽݐିଵ
൬
1
10
൰ − 90
− ݊ܽݐିଵ
൬
GBW
߱′ଶ
൰
PM=90
-݊ܽݐିଵ
ቀ
ୋ
ఠ′ುమ
ቁ − ݊ܽݐିଵ
ቀ
ୋ
ఠ′ೋభ
ቁ
For phase margin of 60
and ߱′ଵ = 10ܹܤܩ
߱′ଶ = 2.2 ܹܤܩ ߱′ଶ = 2.2 ܹܤܩ
ܥ = .22ܥ and ݃ଶ = 10݃ଵ
As seen that with higher value ݃ଶ the value of ܥ we will get become smaller but it leads to
large current flow in output stage and hence more static power loss occurs in amplifier as with
large value of ܥ it accurse large area on chip, if we chose load resistance and capacitance too
large than open loop zero come in picture and then,
PM=90
− ݊ܽݐିଵ
ቀ
ୋ
ఠ′ೋభ
ቁ then
మ
భ
=
ଵ
୲ୟ୬ሺଽబିெሻ
Fig 6. Open loop frequency response of two-stage opam with & without load capacitance and resistance
3. PROPOSED BUFFER AMPLIFIER WITH DYNAMIC FLOATING
To reduce the static power loss we combined N- type and P-type differential pair with dynamic
floating concept to reduce the current flowing at the output stage, two floating bias current ln1
and ln2 are used to charge and discharge the output node in combination with lb1 and lb2, during
transition phase from low to high Mp-bias will provide extra current to charge the capacitive load
and during high to low Mn-bias will sink the extra current to discharge the capacitive load
quickly this is the methodology for which we quickly charge and discharge the output load
without increasing the static current that flows through the complementary common source
8. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
16
amplifier M01 and M02. The two output are isolated by the combination of 6 transistors as shown
in the figure.7 Mn-bias, Mn-bias,MDN1, MDN2, MDP1 and MDP2 for same rising and falling
time ln1=ln2,lb1=lb2
lb1 = lb2 = ln1 1 +
൫ௐ
ൗ ൯
ಾವಿమ
൫ௐ
ൗ ൯
ಾವಿభ
+
൫ௐ
ൗ ൯
ಾವುమ
൫ௐ
ൗ ൯
ಾವುభ
൨
The schematic of the proposed buffer is shown in the figure. 8,M1-M5 shows NMOS differential
pair,M6-M10 shows PMOS differential pair,C1-C4 shows miller capacitance, the biasing current
of NMOS and PMOS pair is Ib as M01 and M02 are mirrored from M5 and M10 which is Ib/2
current that will flow, as seen the output stage biased by dynamic floating and 2 single-stage
differential pair, the circuit will suffer from output DC offset voltage which is removed by proper
sizing as
൫ܹ
ܮൗ ൯
ெଵ
൫ܹ
ܮൗ ൯
ସ
=
൫ܹ
ܮൗ ൯
ெଶ
൫ܹ
ܮൗ ൯
ଽ
= ln1 1 +
൫ܹ
ܮൗ ൯
ெேଶ
൫ܹ
ܮൗ ൯
ெேଵ
+
൫ܹ
ܮൗ ൯
ெଶ
൫ܹ
ܮൗ ൯
ெଵ
To design operational amplifier for LCD the following requirement should meet according to
number of bits or resolution of DAC used in LCD panel[23],The open loop gain will be estimated
as
ܣை ≥ 2ேାଵ
Fig 7. Architecture of proposed dynamic floating buffer amplifier
9. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
17
Let open loop gain will be 1000 then gain error will be
gain error =
ଵ
.ହ×ଵ
= .0002 ≤
ೝ
ଶಿశభ
so min value of VDD=512× .002 = 1.02 ݐ݈ݒ and with specific settling time which should be
less than scanning time let it will be 1µs,the gain bandwidth
ܹܤܩ ≥
݈݊2ேାଵ
2ߨݐ௦
for 8 bit the frequency does not exceed 1Mhz. So the design specification for buffer amplifier is
DC gain ≥ 1000=60db, VDD=3.3 volt , GBW=1Mhz PM=60o
,CMOS technology 180nm,
load capacitance= 30pf and load resistance of 30kΩ.
Fig 8. Schematic of proposed dynamic floating buffer amplifier
10. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
18
M1 1.5
1ൗ M9 5
1ൗ M01 28
1ൗ
M2 1.9
1ൗ M10 5
1ൗ M02 28
1ൗ
M3 1.9
1ൗ MPBIAS 4.5
1ൗ C1 1p
M4 5
1ൗ MNBIAS 4
1ൗ C2 6p
M5 5
1ൗ MDN1 4.5
1ൗ C3 1p
M6 2
1ൗ MDN2 9
1ൗ C4 6p
M7 25
1ൗ MDP1 8
1ൗ CL 30P
M8 25
1ൗ MDP2 4
1ൗ RL 30Ω
4. EXPERIMENTAL RESULT
The proposed buffer amplifier is fabricated using a 180nm CMOS technology. The chip area
occupied by the buffer is 30×72 µ݉ଶ
, fig 9 shows the output with 50kz input square wave with
load capacitance of 30pF and 30kΩ resistance, fig 10 shows triangular response of proposed
buffer, the slew rate obtained is 4.8v/µs with setting time of 4.5 µs and 4.2 µs for up and down
stream of square wave, the biasing current per channel is 5µA. And power consumed by buffer is
72 µw. The simulation results using transient and AC analysis is shown in figure from 9 to15
using cadence spectre simulation tool.
5. CONCLUSION
This paper represents a low power buffer amplifier, with low quiescent current with the dynamic
floating output node we adjust the output bias current without changing the input differential pair
biasing current configuration, according to load capacitance the output current will be varied with
the help of floating bias current network. The use-fullness of such type of buffer is, it work as
positive and negative type buffer without any switched capacitor network which is used to toggle
the differential amplifier in between positive and negative buffer.
COMPARISON TABLE
This work [1] [2] [3] [4]
Process 180nm CMOS .35µmCMOS .35µmCMOS .35µm CMOS .35µm CMOS
VDD 3.3 5 3.3 5
Bias current 5µA/per channel 2µA 7.4µA NA 5µA
loads 30KΩ, 30pF 10KΩ, 24pF 600pF 400pF 10pF
o/p swing 96% NA NA NA NA
Settling time 4.5µs 2µs 8µs 1µs .5µs
Slew rate 5v/ µs NA NA NA 2v/ µs
Area 30×72 µ݉ଶ
22×190µ݉ଶ
100×45µ݉ଶ
86×74 µ݉ଶ
.04 m݉ଶ
11. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
Fig 9. Simulation result with rectangular wave of frequency 50khz with load
Fig 10. Simulation result with rectangular wave of frequency 50khz with two input output
International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
Fig 9. Simulation result with rectangular wave of frequency 50khz with load
result with rectangular wave of frequency 50khz with two input output
International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
19
result with rectangular wave of frequency 50khz with two input output
12. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
Fig 11. Simulation result with triangular wave of frequency 50khz with load
Fig 12. Simulation result with triangular wave of frequency 50khz with two input output
International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
Fig 11. Simulation result with triangular wave of frequency 50khz with load
Fig 12. Simulation result with triangular wave of frequency 50khz with two input output
International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
20
Fig 12. Simulation result with triangular wave of frequency 50khz with two input output
13. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
Fig 13. AC response of the proposed floating load output stage
Fig 14. Power diagram with rectangular wave of frequency 50khz with load
International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
response of the proposed floating load output stage
Fig 14. Power diagram with rectangular wave of frequency 50khz with load
International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
21
14. International Journal of VLSI design & Communication Systems (VLSICS) Vol.6, No.1, February 2015
Fig 15. Layout diagram of proposed floating output node of buffer amplifier
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AUTHORS
Dr. R.K. Baghel
Designation: Professor MANIT Bhopal
Qualification: B.E, M.Tech, Ph.D
Research Interest: Low Power Analog circuit design ,LCD driver circuit design mixed
mode analog circuit, Low power Operational amplifier, Data converter
Hari shanker srivastava received B.Tech degree 2007 and M.Tech degree 2010 from
MANIT Bhopal. He is working towards the Ph.D degree. His research interest is
mixed mode analog circuit design and reversible logic design