Here are the key changes to the noise analysis of the common source amplifier example if:
1) Transistor is in triode region:
- gm would be a function of VGS and VDS instead of a constant
- inMOS would depend on gm as a function of voltages
2) Include flicker noise:
- Add a flicker noise current source inMOS,f
- PSD of inMOS,f is Kf/f instead of constant
- Integrate PSD from fmin to fmax
3) Replace RL with PMOS load:
- Replace RL with the output resistance ro of the PMOS load transistor
- Add thermal noise current source of the PMOS load transistor
The document discusses sampling theory and its applications. It introduces key concepts such as:
1. Signals can be represented by discrete sample values taken at regular intervals, and reconstructed using an ideal low-pass filter, as described by the sampling theorem.
2. The sampling theorem states that a band-limited signal with no frequencies above B Hz can be uniquely determined by samples taken at least every 1/(2B) seconds.
3. Anti-aliasing filters are used to limit the bandwidth of signals before sampling to avoid aliasing when the sampling rate is lower than predicted by the sampling theorem.
The receiver structure consists of four main components:
1. A matched filter that maximizes the SNR by matching the source impulse and channel.
2. An equalizer that removes intersymbol interference.
3. A timing component that determines the optimal sampling time using an eye diagram.
4. A decision component that determines whether the received bit is a 0 or 1 based on a threshold.
The performance of the receiver depends on factors like noise, equalization technique used, and timing accuracy. The bit error rate can be estimated using tools like error functions.
This document discusses correlative-level coding and its applications in baseband pulse transmission systems. Correlative-level coding introduces controlled intersymbol interference to increase signaling rate. It allows partial response signaling and maximum likelihood detection at the receiver. Specific techniques discussed include duobinary signaling and modified duobinary signaling. The document also covers tapped-delay line equalization using adaptive algorithms like least mean square to compensate for channel distortion. Decision feedback equalization and its implementation are summarized as well. Eye patterns are described as a tool to evaluate signal quality in such systems.
The document contains details about sampling a bandpass signal with varying center frequency fo from 5 kHz to 50 kHz at a sampling rate of 25 kHz.
It analyzes the ranges of fo for which the sampling rate is adequate by calculating the variation in bandwidth (k) as fo changes. It concludes that the sampling rate of 25 kHz is adequate when fo is between 5-7.5 kHz, 15-20 kHz, 25-32.5 kHz, and 35-50 kHz.
This document discusses techniques for pulse shaping to reduce inter-symbol interference (ISI) in digital communication systems. It introduces the Nyquist criteria that pulse shapes must satisfy to avoid ISI, including having zero crossings at symbol intervals, zero areas within symbol periods, and zero values at decision thresholds. Methods like raised cosine filtering are presented that trade off bandwidth for smoothness to meet the Nyquist criteria. The document also discusses partial response signaling techniques like duobinary that relax the criteria but require differential encoding to avoid error propagation.
Nyquist criterion for distortion less baseband binary channelPriyangaKR1
binary transmission system
From design point of view – frequency response of the channel and transmitted pulse shape are specified; the frequency response of the transmit and receive filters has to be determined so as to reconstruct [bk]
1. VSB modulation is used for picture transmission in commercial TV in India as it provides a compromise between SSB and DSB. Speech signals use FM modulation for its noise immunity.
2. In a DSB AM system, if the modulation index is doubled, the ratio of sideband power to carrier power increases by a factor of 4.
3. The maximum power efficiency of an AM modulator is 33%.
This document discusses Nyquist's criterion for distortionless transmission of binary signals over a baseband channel. It states that intersymbol interference (ISI) can be eliminated by choosing a transmit filter response P(f) that satisfies the Nyquist criterion. An ideal rectangular pulse shape meets the criterion but is physically unrealizable. A more practical raised cosine pulse is proposed, which introduces a rolloff factor to trade off excess bandwidth for slower decay. The full-cosine case provides additional zero-crossings that aid synchronization but doubles the bandwidth.
The document discusses sampling theory and its applications. It introduces key concepts such as:
1. Signals can be represented by discrete sample values taken at regular intervals, and reconstructed using an ideal low-pass filter, as described by the sampling theorem.
2. The sampling theorem states that a band-limited signal with no frequencies above B Hz can be uniquely determined by samples taken at least every 1/(2B) seconds.
3. Anti-aliasing filters are used to limit the bandwidth of signals before sampling to avoid aliasing when the sampling rate is lower than predicted by the sampling theorem.
The receiver structure consists of four main components:
1. A matched filter that maximizes the SNR by matching the source impulse and channel.
2. An equalizer that removes intersymbol interference.
3. A timing component that determines the optimal sampling time using an eye diagram.
4. A decision component that determines whether the received bit is a 0 or 1 based on a threshold.
The performance of the receiver depends on factors like noise, equalization technique used, and timing accuracy. The bit error rate can be estimated using tools like error functions.
This document discusses correlative-level coding and its applications in baseband pulse transmission systems. Correlative-level coding introduces controlled intersymbol interference to increase signaling rate. It allows partial response signaling and maximum likelihood detection at the receiver. Specific techniques discussed include duobinary signaling and modified duobinary signaling. The document also covers tapped-delay line equalization using adaptive algorithms like least mean square to compensate for channel distortion. Decision feedback equalization and its implementation are summarized as well. Eye patterns are described as a tool to evaluate signal quality in such systems.
The document contains details about sampling a bandpass signal with varying center frequency fo from 5 kHz to 50 kHz at a sampling rate of 25 kHz.
It analyzes the ranges of fo for which the sampling rate is adequate by calculating the variation in bandwidth (k) as fo changes. It concludes that the sampling rate of 25 kHz is adequate when fo is between 5-7.5 kHz, 15-20 kHz, 25-32.5 kHz, and 35-50 kHz.
This document discusses techniques for pulse shaping to reduce inter-symbol interference (ISI) in digital communication systems. It introduces the Nyquist criteria that pulse shapes must satisfy to avoid ISI, including having zero crossings at symbol intervals, zero areas within symbol periods, and zero values at decision thresholds. Methods like raised cosine filtering are presented that trade off bandwidth for smoothness to meet the Nyquist criteria. The document also discusses partial response signaling techniques like duobinary that relax the criteria but require differential encoding to avoid error propagation.
Nyquist criterion for distortion less baseband binary channelPriyangaKR1
binary transmission system
From design point of view – frequency response of the channel and transmitted pulse shape are specified; the frequency response of the transmit and receive filters has to be determined so as to reconstruct [bk]
1. VSB modulation is used for picture transmission in commercial TV in India as it provides a compromise between SSB and DSB. Speech signals use FM modulation for its noise immunity.
2. In a DSB AM system, if the modulation index is doubled, the ratio of sideband power to carrier power increases by a factor of 4.
3. The maximum power efficiency of an AM modulator is 33%.
This document discusses Nyquist's criterion for distortionless transmission of binary signals over a baseband channel. It states that intersymbol interference (ISI) can be eliminated by choosing a transmit filter response P(f) that satisfies the Nyquist criterion. An ideal rectangular pulse shape meets the criterion but is physically unrealizable. A more practical raised cosine pulse is proposed, which introduces a rolloff factor to trade off excess bandwidth for slower decay. The full-cosine case provides additional zero-crossings that aid synchronization but doubles the bandwidth.
On The Fundamental Aspects of DemodulationCSCJournals
When the instantaneous amplitude, phase and frequency of a carrier wave are modulated with the information signal for transmission, it is known that the receiver works on the basis of the received signal and a knowledge of the carrier frequency. The question is: If the receiver does not have the a priori information about the carrier frequency, is it possible to carry out the demodulation process? This tutorial lecture answers this question by looking into the very fundamental process by which the modulated wave is generated. It critically looks into the energy separation algorithm for signal analysis and suggests modification for distortionless demodulation of an FM signal, and recovery of sub-carrier signals
This document provides an introduction to signals and systems. It begins by classifying different types of signals as continuous-time/discrete-time, analog/digital, deterministic/random, periodic/aperiodic, power/energy. It then discusses representations of signals in the time and frequency domains, including the Fourier series representation of periodic signals. Key concepts covered include the unit step, rectangular, triangular and sinc functions, as well as signal operations like time shifting, scaling and inversion. The document concludes by introducing Parseval's theorem relating the power of a signal to the power of its Fourier coefficients.
This document summarizes key aspects of the discrete Fourier transform (DFT). It defines the DFT, provides the formula for calculating it, and explains that the DFT transforms a discrete-time signal from the time domain to the frequency domain. It also outlines several important properties of the DFT, including linearity, shift property, duality, symmetry, and circular convolution. Examples are provided to illustrate duality and symmetry. References for further information on the discrete Fourier transform are also included.
The document summarizes key properties of the discrete Fourier transform (DFT). It describes linearity, periodicity, time/frequency shifts, conjugation, multiplication, convolution, correlation, and Parseval's theorem. Linearity means the DFT of a linear combination of signals is the linear combination of the DFTs. Periodicity means an N-point DFT is periodic with N samples. Shifts change the time or frequency domain representation. Multiplication in the time domain is convolution in the frequency domain. Correlation relates the time and frequency domain representations. Parseval's theorem relates the energy in the time and frequency domains.
This document discusses efficient algorithms for computing the discrete Fourier transform (DFT), specifically the fast Fourier transform (FFT). It covers several FFT algorithms including decimation-in-time, decimation-in-frequency, and the Goertzel algorithm. The decimation-in-time algorithm recursively breaks down the DFT computation into smaller DFTs by decomposing the input sequence. This allows the computation to be performed in O(NlogN) time rather than O(N^2) time for a direct DFT computation. The document also discusses optimizations like in-place computation to reduce memory usage.
Slides of a talk at CMU Theory lunch (http://www.cs.cmu.edu/~theorylunch/20111116.html) and Capital Area Theory seminar (http://www.cs.umd.edu/areas/Theory/CATS/#Grigory).
This document provides an overview of discrete-time signals and systems in digital signal processing (DSP). It discusses key concepts such as:
1) Discrete-time signals which are represented by sequences of numbers and how common signals like impulses and steps are represented.
2) Discrete-time systems which take a discrete-time signal as input and produce an output signal through a mathematical algorithm, with the impulse response characterizing the system.
3) Important properties of linear time-invariant (LTI) systems including superposition, time-shifting of inputs and outputs, and representation using convolution sums or difference equations.
Angle modulation techniques such as frequency modulation (FM) and phase modulation (PM) were introduced. FM varies the carrier frequency according to the message signal, while PM varies the carrier phase. The chapter covered the concepts of instantaneous frequency, bandwidth of angle modulated signals, generation of FM signals through direct and indirect methods, and demodulation of FM signals using discriminators and phase-locked loops. Key advantages of FM over AM include improved noise immunity and resistance to interference at the cost of increased transmission bandwidth.
The document discusses decimation in time (DIT) and decimation in frequency (DIF) fast Fourier transform (FFT) algorithms. DIT breaks down an N-point sequence into smaller DFTs of even and odd indexed samples, recursively computing smaller and smaller DFTs until individual points remain. DIF similarly decomposes the computation but by breaking the frequency domain spectrum into smaller DFTs. Both algorithms reduce the computational complexity of computing the discrete Fourier transform from O(N^2) to O(NlogN) operations.
The document describes an experiment on linear time invariant systems. The objectives are to: 1) Convolve a signal with an impulse response, 2) Find step responses using the impulse response for rectangular, exponential and sinusoidal inputs, 3) Show stable and unstable conditions using pole-zero plots, 4) Apply filtering to an image using circular convolution with overlap add and save methods. Background topics discussed are aliasing, impulse/step inputs, and even/odd signals. Questions involve plotting a signal, its Fourier transform, and filtering an image.
This document discusses amplitude modulated communication systems. It describes how a carrier signal is modulated by a baseband modulating signal to allow for information exchange over a channel. There are different types of modulation including continuous wave, pulse, and digital modulation. Amplitude modulation varies the amplitude of the carrier signal based on the instantaneous value of the modulating signal. This allows for multiplexing of multiple messages and use of more practical antenna sizes. Specific amplitude modulation techniques are described like conventional AM, DSB-SC, SSB, and VSB along with their tradeoffs in terms of carrier suppression, bandwidth, cost, and applications.
Speech signal time frequency representationNikolay Karpov
This lecture discusses spectrogram analysis and the short-term discrete Fourier transform. It defines normalized time and frequency, examines the effect of window length on time-frequency resolution, and derives descriptions of frequency and time resolution. It also reviews properties of the discrete Fourier transform and illustrates the uncertainty principle with examples.
This document discusses the discrete-time Fourier transform (DTFT). It begins by introducing the DTFT and how it can be used to represent aperiodic signals as the sum of complex exponentials. Several properties of the DTFT are then discussed, including linearity, time/frequency shifting, periodicity, and conjugate symmetry. Examples are provided to illustrate how to compute the DTFT of simple signals. The document also discusses how the DTFT can be used to represent periodic signals and impulse trains.
This document discusses digital signal processing concepts including the discrete Fourier transform (DFT) and fast Fourier transform (FFT). It defines DFT as a numerically computable transform that takes a time domain sequence and represents it as a sequence of discrete frequency samples. It also describes how the FFT uses techniques like divide-and-conquer to reduce the computational load of the DFT from O(N^2) to O(NlogN). MATLAB can be used to easily calculate DFTs using the fft function.
This document provides an overview of angle modulation techniques including frequency modulation (FM) and phase modulation (PM). It defines PM and FM mathematically. For PM, the phase deviation is a linear function of the baseband message signal. For FM, the instantaneous frequency deviation is a linear function of the message signal. The key advantages of FM and PM over amplitude modulation are constant envelope and better noise immunity. However, FM and PM require increased bandwidth compared to amplitude modulation. The document derives expressions for the pre-envelope and spectrum of an FM signal and discusses bandwidth requirements of FM.
Describes Pulse Compression in Radar Systems.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://solohermelin.com.
Since some figures were not downloaded, I recommend to see this presentation on my website under RADAR Folder, Signal Processing subfolder.
continuos phase frequency shift keying(cpfsk)Moka Dinesh
This document discusses continuous-phase frequency-shift keying (CPFSK) modulation. CPFSK is a memory-based modulation scheme where the phase is constrained to be continuous, unlike conventional FSK which has abrupt phase shifts. This avoids large spectral side lobes outside the main signal band. CPFSK uses a voltage-controlled oscillator where the phase is determined by integrating the modulated signal. The phase trajectories form a piecewise linear phase trellis. Minimum-shift keying (MSK) is a special case of binary CPFSK with a modulation index of 1/2 and rectangular pulses.
The document discusses the Radix-2 discrete Fourier transform (DFT) algorithm. It explains that the Radix-2 DFT divides an N-point sequence into two N/2-point sequences, computes the DFT of each subsequence, and then combines the results to compute the N-point DFT. It involves decimating the sequence, computing smaller DFTs, and combining results over multiple stages. The Radix-2 algorithm reduces the computation from O(N^2) for the direct DFT to O(NlogN) operations.
The document discusses CMOS transistor fabrication and scaling. It addresses two key problems with CMOS operation: latch-up and parasitic capacitance. Latch-up can permanently damage transistors, while parasitic capacitance limits high frequency performance. Methods to overcome these issues include latch-up protection circuits, increasing distances between wells/junctions, and partially disconnecting parasitic devices from ground terminals. CMOS technologies like P-well, N-well, and SOI were compared in terms of mitigating latch-up and parasitic capacitance. The document also covers MOS scaling theory and its impacts on circuit performance and power consumption over time as feature sizes decreased from submicron to deep submicron to nanotechnology levels.
CMOS (complementary metal-oxide semiconductor) is a type of memory that stores BIOS and system configuration settings using a small battery as backup. It can be accessed by pressing Delete or Ctrl-Alt-Esc during POST to view and change settings. The main CMOS setup menu allows configuring options like system date/time, SATA devices, and security settings. If the BIOS password is forgotten, the CMOS can be cleared by shorting the CMOS jumper or removing the CMOS battery.
On The Fundamental Aspects of DemodulationCSCJournals
When the instantaneous amplitude, phase and frequency of a carrier wave are modulated with the information signal for transmission, it is known that the receiver works on the basis of the received signal and a knowledge of the carrier frequency. The question is: If the receiver does not have the a priori information about the carrier frequency, is it possible to carry out the demodulation process? This tutorial lecture answers this question by looking into the very fundamental process by which the modulated wave is generated. It critically looks into the energy separation algorithm for signal analysis and suggests modification for distortionless demodulation of an FM signal, and recovery of sub-carrier signals
This document provides an introduction to signals and systems. It begins by classifying different types of signals as continuous-time/discrete-time, analog/digital, deterministic/random, periodic/aperiodic, power/energy. It then discusses representations of signals in the time and frequency domains, including the Fourier series representation of periodic signals. Key concepts covered include the unit step, rectangular, triangular and sinc functions, as well as signal operations like time shifting, scaling and inversion. The document concludes by introducing Parseval's theorem relating the power of a signal to the power of its Fourier coefficients.
This document summarizes key aspects of the discrete Fourier transform (DFT). It defines the DFT, provides the formula for calculating it, and explains that the DFT transforms a discrete-time signal from the time domain to the frequency domain. It also outlines several important properties of the DFT, including linearity, shift property, duality, symmetry, and circular convolution. Examples are provided to illustrate duality and symmetry. References for further information on the discrete Fourier transform are also included.
The document summarizes key properties of the discrete Fourier transform (DFT). It describes linearity, periodicity, time/frequency shifts, conjugation, multiplication, convolution, correlation, and Parseval's theorem. Linearity means the DFT of a linear combination of signals is the linear combination of the DFTs. Periodicity means an N-point DFT is periodic with N samples. Shifts change the time or frequency domain representation. Multiplication in the time domain is convolution in the frequency domain. Correlation relates the time and frequency domain representations. Parseval's theorem relates the energy in the time and frequency domains.
This document discusses efficient algorithms for computing the discrete Fourier transform (DFT), specifically the fast Fourier transform (FFT). It covers several FFT algorithms including decimation-in-time, decimation-in-frequency, and the Goertzel algorithm. The decimation-in-time algorithm recursively breaks down the DFT computation into smaller DFTs by decomposing the input sequence. This allows the computation to be performed in O(NlogN) time rather than O(N^2) time for a direct DFT computation. The document also discusses optimizations like in-place computation to reduce memory usage.
Slides of a talk at CMU Theory lunch (http://www.cs.cmu.edu/~theorylunch/20111116.html) and Capital Area Theory seminar (http://www.cs.umd.edu/areas/Theory/CATS/#Grigory).
This document provides an overview of discrete-time signals and systems in digital signal processing (DSP). It discusses key concepts such as:
1) Discrete-time signals which are represented by sequences of numbers and how common signals like impulses and steps are represented.
2) Discrete-time systems which take a discrete-time signal as input and produce an output signal through a mathematical algorithm, with the impulse response characterizing the system.
3) Important properties of linear time-invariant (LTI) systems including superposition, time-shifting of inputs and outputs, and representation using convolution sums or difference equations.
Angle modulation techniques such as frequency modulation (FM) and phase modulation (PM) were introduced. FM varies the carrier frequency according to the message signal, while PM varies the carrier phase. The chapter covered the concepts of instantaneous frequency, bandwidth of angle modulated signals, generation of FM signals through direct and indirect methods, and demodulation of FM signals using discriminators and phase-locked loops. Key advantages of FM over AM include improved noise immunity and resistance to interference at the cost of increased transmission bandwidth.
The document discusses decimation in time (DIT) and decimation in frequency (DIF) fast Fourier transform (FFT) algorithms. DIT breaks down an N-point sequence into smaller DFTs of even and odd indexed samples, recursively computing smaller and smaller DFTs until individual points remain. DIF similarly decomposes the computation but by breaking the frequency domain spectrum into smaller DFTs. Both algorithms reduce the computational complexity of computing the discrete Fourier transform from O(N^2) to O(NlogN) operations.
The document describes an experiment on linear time invariant systems. The objectives are to: 1) Convolve a signal with an impulse response, 2) Find step responses using the impulse response for rectangular, exponential and sinusoidal inputs, 3) Show stable and unstable conditions using pole-zero plots, 4) Apply filtering to an image using circular convolution with overlap add and save methods. Background topics discussed are aliasing, impulse/step inputs, and even/odd signals. Questions involve plotting a signal, its Fourier transform, and filtering an image.
This document discusses amplitude modulated communication systems. It describes how a carrier signal is modulated by a baseband modulating signal to allow for information exchange over a channel. There are different types of modulation including continuous wave, pulse, and digital modulation. Amplitude modulation varies the amplitude of the carrier signal based on the instantaneous value of the modulating signal. This allows for multiplexing of multiple messages and use of more practical antenna sizes. Specific amplitude modulation techniques are described like conventional AM, DSB-SC, SSB, and VSB along with their tradeoffs in terms of carrier suppression, bandwidth, cost, and applications.
Speech signal time frequency representationNikolay Karpov
This lecture discusses spectrogram analysis and the short-term discrete Fourier transform. It defines normalized time and frequency, examines the effect of window length on time-frequency resolution, and derives descriptions of frequency and time resolution. It also reviews properties of the discrete Fourier transform and illustrates the uncertainty principle with examples.
This document discusses the discrete-time Fourier transform (DTFT). It begins by introducing the DTFT and how it can be used to represent aperiodic signals as the sum of complex exponentials. Several properties of the DTFT are then discussed, including linearity, time/frequency shifting, periodicity, and conjugate symmetry. Examples are provided to illustrate how to compute the DTFT of simple signals. The document also discusses how the DTFT can be used to represent periodic signals and impulse trains.
This document discusses digital signal processing concepts including the discrete Fourier transform (DFT) and fast Fourier transform (FFT). It defines DFT as a numerically computable transform that takes a time domain sequence and represents it as a sequence of discrete frequency samples. It also describes how the FFT uses techniques like divide-and-conquer to reduce the computational load of the DFT from O(N^2) to O(NlogN). MATLAB can be used to easily calculate DFTs using the fft function.
This document provides an overview of angle modulation techniques including frequency modulation (FM) and phase modulation (PM). It defines PM and FM mathematically. For PM, the phase deviation is a linear function of the baseband message signal. For FM, the instantaneous frequency deviation is a linear function of the message signal. The key advantages of FM and PM over amplitude modulation are constant envelope and better noise immunity. However, FM and PM require increased bandwidth compared to amplitude modulation. The document derives expressions for the pre-envelope and spectrum of an FM signal and discusses bandwidth requirements of FM.
Describes Pulse Compression in Radar Systems.
For comments please contact me at solo.hermelin@gmail.com.
For more presentations on different subjects visit my website at http://solohermelin.com.
Since some figures were not downloaded, I recommend to see this presentation on my website under RADAR Folder, Signal Processing subfolder.
continuos phase frequency shift keying(cpfsk)Moka Dinesh
This document discusses continuous-phase frequency-shift keying (CPFSK) modulation. CPFSK is a memory-based modulation scheme where the phase is constrained to be continuous, unlike conventional FSK which has abrupt phase shifts. This avoids large spectral side lobes outside the main signal band. CPFSK uses a voltage-controlled oscillator where the phase is determined by integrating the modulated signal. The phase trajectories form a piecewise linear phase trellis. Minimum-shift keying (MSK) is a special case of binary CPFSK with a modulation index of 1/2 and rectangular pulses.
The document discusses the Radix-2 discrete Fourier transform (DFT) algorithm. It explains that the Radix-2 DFT divides an N-point sequence into two N/2-point sequences, computes the DFT of each subsequence, and then combines the results to compute the N-point DFT. It involves decimating the sequence, computing smaller DFTs, and combining results over multiple stages. The Radix-2 algorithm reduces the computation from O(N^2) for the direct DFT to O(NlogN) operations.
The document discusses CMOS transistor fabrication and scaling. It addresses two key problems with CMOS operation: latch-up and parasitic capacitance. Latch-up can permanently damage transistors, while parasitic capacitance limits high frequency performance. Methods to overcome these issues include latch-up protection circuits, increasing distances between wells/junctions, and partially disconnecting parasitic devices from ground terminals. CMOS technologies like P-well, N-well, and SOI were compared in terms of mitigating latch-up and parasitic capacitance. The document also covers MOS scaling theory and its impacts on circuit performance and power consumption over time as feature sizes decreased from submicron to deep submicron to nanotechnology levels.
CMOS (complementary metal-oxide semiconductor) is a type of memory that stores BIOS and system configuration settings using a small battery as backup. It can be accessed by pressing Delete or Ctrl-Alt-Esc during POST to view and change settings. The main CMOS setup menu allows configuring options like system date/time, SATA devices, and security settings. If the BIOS password is forgotten, the CMOS can be cleared by shorting the CMOS jumper or removing the CMOS battery.
Introduction to CMOS VLSI Design:
This Presentations is design in way to provide basic summary of CMOS Vlsi design
This Presentation is Made at Eutectics.blogspot.in
the following is the structure of presentation :
2: Outline
3: Introduction
4: MOS capacitor
5: Terminal Voltage
6: nMOS Cutoff
7: nMOS Linear
8: nMOS Saturation
9: I-V Characteristics
10 : Channel Charge
11: Carrier velocity
12: nMOS Linear I-V
13: nMOS Saturation
14: nMOS I-V Summary
15: Example
16: pMOS I-V
17: Capacitance
18: Gate Capacitance
19: Diffusion Capacitane
20: Pass Transistor
21: Pass transistor ckts
22: Effective Resistance
23: RC Delay Model
24: RC values
25: Inverter Delay Estimate
The document discusses MOS transistors and their operation. It introduces MOS structure, showing the metal-oxide-semiconductor makeup. It describes how applying a positive voltage to the gate can create an inversion layer channel between the source and drain, allowing current to flow. The threshold voltage is defined as the minimum gate voltage needed to form an conducting channel. The document covers MOS transistor regions of operation like accumulation, depletion and inversion modes in detail. It also discusses key characteristics like current-voltage relationships.
MOS and CMOS technologies are types of field-effect transistors. MOS transistors use a metal gate separated from a semiconductor channel by an oxide layer. There are two types of MOS transistors: nMOS with a negatively doped silicon channel and pMOS with a positively doped channel. CMOS circuits combine both nMOS and pMOS transistors to construct logic gates. CMOS circuits have low power dissipation, higher noise immunity, and higher fan-out compared to other logic families.
The document discusses CMOS fabrication which involves forming wells and transistors on a silicon substrate through photolithography, etching, and ion implantation processes. NMOS and PMOS transistors are formed by doping different regions with n-type or p-type dopants. Together, these complementary transistors are used to build basic logic gates in integrated circuits with low power consumption. The CMOS process allows for high density, low cost microchips through standard fabrication steps.
A MOSFET is a semiconductor device that can amplify or switch electronic signals. It has three terminals - drain, source, and gate. Depending on whether the semiconductor material between the drain and source is n-type or p-type, a MOSFET can be an n-channel or p-channel type. Applying a positive voltage to the gate of an n-channel MOSFET or a negative voltage to the gate of a p-channel MOSFET allows current to flow between the drain and source. MOSFETs are commonly used as switches in digital circuits like processors and as amplifiers in analog circuits. They are also used in memory devices, power supplies, and other electronic applications.
This document provides an overview of CMOS technology. It discusses how CMOS circuits use complementary pairs of NMOS and PMOS transistors to implement logic gates like inverters. The CMOS inverter uses one transistor to pull the output low and the other to pull it high, allowing for low power operation. Larger CMOS logic gates consist of pull-down and pull-up networks of NMOS and PMOS transistors respectively. Transistor sizing is also covered, with sizing done to ensure equal driving capability between pull-up and pull-down networks.
This document provides an introduction to transistors and MOSFETs. It begins by describing the invention of the transistor in 1947 and defining what a transistor is. It then discusses the main types of transistors - BJT and FET, including MOSFET and JFET. The rest of the document focuses on MOSFETs, explaining what they are, their terminals and symbols, types of MOSFETs like n-MOSFET and p-MOSFET, and how MOSFETs work and are fabricated through processes like photolithography, etching, diffusion, and oxidation. It includes diagrams of MOSFET structure and operation. In the end it briefly discusses CMOS fabrication process flow.
The document describes the CMOS design and fabrication process. Key points include:
- CMOS uses complementary n-type and p-type MOS transistors to reduce power consumption.
- Transistors are built on a silicon substrate using dopants to create n-type and p-type regions. PN junctions form diodes and MOS capacitors.
- The CMOS fabrication process involves layering and patterning of silicon, oxides, and metals through steps like oxidation, lithography, etching, and doping.
This document provides an overview of VLSI design for a course. It discusses topics including CMOS transistors and logic gates, VLSI levels of abstraction, the VLSI design process, design styles like full custom and ASIC, and trends like Moore's Law. The roadmap outlines topics to be covered like CMOS processing, combinational and sequential circuit design, and a design project to complete a chip. Course objectives are listed relating to VLSI analysis, layout design, and system design skills.
The document discusses CMOS VLSI design technology and future trends. It provides an overview of CMOS technology and basic MOSFET operation. It then discusses how nanotechnology and integrated tri-gate transistors can help address limitations of CMOS scaling by reducing feature sizes and parasitic leakage. The document concludes that continued CMOS scaling will eventually be limited and alternatives like nanotechnology may be needed to retain device characteristics at smaller sizes.
The document discusses transistors, including their history and evolution. It describes how the transistor was invented in 1947 and became the building block of electronics. Moore's Law, which predicted transistors would double every two years, driving down costs, is also mentioned. The key types of transistors - bipolar junction transistors and field effect transistors - are defined. Their basic construction, symbols, operation, and applications as switches and amplifiers are outlined. New developments in transistor technology like 3D transistors are also summarized.
This document provides lecture notes on MOS design equations and parameters. It includes:
- MOS transistor symbol definitions and varieties
- Support equations for threshold voltage, subthreshold slope, gate overdrive voltage, velocity saturation, drain current factor, channel length modulation, and thermal voltage
- Current equations for strong, weak, and moderate inversion regions
- Sample MOSFET parameters for 0.35μm and 0.18μm processes
- Problems involving calculating small signal parameters, voltage gain, and transistor sizing for different circuits like common source amplifiers, NAND gates, and current mirrors.
This document discusses delta modulation and adaptive delta modulation techniques for analogue to digital conversion.
Delta modulation encodes the difference between the input signal and a reference signal into a single bit per sample, creating a staircase-like approximation of the original signal. Adaptive delta modulation varies the step size according to the input signal level to prevent slope overload. Differential pulse code modulation encodes the difference between the current and predicted sample values, sending this difference value instead of absolute sample amplitudes.
The document discusses frequency modulation techniques, specifically GMSK modulation. It provides an overview of digital modulation, describes the key parameters and expression for GMSK modulation, and discusses implementing a GMSK modulator. It explains that GMSK modulation uses continuous phase modulation with a Gaussian frequency shaping filter. The document also provides the mathematical expressions for the GMSK modulated signal and describes calculating the baseband components and elementary phase pulse using Matlab.
This three day course is intended for practicing systems engineers who want to learn how to apply model-driven systems Successful systems engineering requires a broad understanding of the important principles of modern spacecraft communications. This three-day course covers both theory and practice, with emphasis on the important system engineering principles, tradeoffs, and rules of thumb. The latest technologies are covered. <p>
ECE375_Lec2_signal processing for engineering.pdfssuserd36536
This document summarizes key concepts from Chapter 2 of a signals and spectra textbook. It defines basic signal properties like DC value, RMS value, decibels, and phasors. It explains that signals can be categorized as either energy waveforms or power waveforms based on whether their total energy or average power over time is finite. Physically realizable signals are of the energy type. Examples are provided to demonstrate calculating DC value, instantaneous power, and average power for simple circuits. The chapter objectives are to cover Fourier transforms and spectra, linear systems, bandwidth, sampling, and the discrete Fourier transform.
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1) Transmission lines carry signals between two points by propagating waves along two parallel conductors. Common types include coaxial cable and printed circuit board traces.
2) Transmission lines are characterized by their per-unit-length inductance, capacitance, resistance, and conductance. The behavior of signals on the line is described by telegrapher's equations.
3) Waves on transmission lines travel at the phase velocity, defined as the ratio of frequency to phase constant. The characteristic impedance is determined by the line's inductance and capacitance.
TEM Transmission lines' properties, the construction techniques, types, uses in the circuits, mathematical representation, limitations and their solutions are described
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nature of MOSFET ,operation, characteristics curveGayathriPriya34
This document discusses the operation and modeling of MOSFET transistors. It begins by describing the basic structure and operation of an n-type MOSFET. It then provides some important equations that model the inversion layer charge and threshold voltage. The document goes on to discuss modeling the transistor behavior in different regimes, including gradual channel approximation, sub-threshold behavior, and saturation. It also compares MOSFETs to BJTs and discusses factors that affect transistor performance such as mobility and threshold voltage control.
OFDM is a high-speed wireless transmission technology that divides the available spectrum into multiple orthogonal subcarriers. It is implemented as OFDMA to support multi-user communication. OFDM provides advantages over single carrier transmission by combating inter-symbol interference and frequency selective fading. It works by encoding data over multiple carrier frequencies, with spacing between carriers chosen so that the carriers are orthogonal to each other. This allows high data rates without overlapping signals at a receiver.
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The document discusses the CMOS inverter, including its basic structure and operation, transient response characteristics, voltage transfer curve, propagation delay, and design considerations for improving performance such as minimizing delay. It provides analysis of how varying factors like transistor widths, supply voltage, and load capacitance affect the inverter's switching threshold, rise/fall times, and propagation delay. The goal of the analysis is to determine the optimal transistor width ratios and device parameters needed to create a symmetric inverter with minimum total propagation delay.
sp12Part2 CIRCUITS AND SYSTEMS FOR COMPUTER ENGINEERING .pptxElisée Ndjabu
This document discusses the high-frequency response of electronic circuits such as amplifiers. It begins by introducing high-frequency small-signal models for MOSFETs and BJTs. It then defines the unity-gain frequency and describes how to find capacitance values using this frequency. The document provides an example of analyzing the effect of one capacitor on amplifier gain. It also discusses the frequency response of common source and common emitter amplifiers, showing their high-frequency small-signal equivalent circuits. Key aspects of amplifier frequency response like gain, poles, zeros, and Bode plots are covered.
This document discusses transmission line theory. It defines the key parameters used to characterize transmission lines, including capacitance, inductance, resistance, and conductance per unit length. It derives the telegrapher's equations that describe voltage and current on a transmission line as a function of position and time. It then solves these equations for time-harmonic waves, defining the propagation constant and introducing the characteristic impedance of the line. It explores the concepts of phase velocity and wavelength on the transmission line.
Notes 2 5317-6351 Transmission Lines Part 1 (TL Theory).pptxDibyadipRoy1
This document provides notes on transmission line theory. Some key points:
- Transmission line theory is needed when the length of a line is significant compared to a wavelength.
- Transmission lines have per-unit-length parameters of capacitance, inductance, resistance, and conductance.
- The telegrapher's equations describe voltage and current on a transmission line as a function of position and time.
- Waves on a transmission line travel at the phase velocity, which depends on the transmission line's characteristics.
- The characteristic impedance Z0 of a transmission line relates the amplitudes of voltage and current waves traveling on the line.
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2006 devmodel
1. CMOS Device Model
• Objective
– Hand calculations for analog design
– Efficiently and accurately simulation
• CMOS transistor models
– Large signal model
– Small signal model
– Simulation model
– Noise model
2. Large Signal Model
• Nonlinear equations for solving dc values of
device currents given voltages
• Level 1: Shichman-Hodges (VT, K', γ, λ, φ, and
NSUB)
• Level 2: with second-order effects (varying
channel charge, short-channel, weak inversion,
varying surface mobility, etc.)
• Level 3: Semi-empirical short-channel model
• Level 4: BSIM models. Based on automatically
generated parameters from a process
characterization. Good weak-strong inversion
transition.
12. MOST Regions of Operation
• Cut-off, or non-conducting: VGS <VT
– ID=0
• Conducting: VGS >=VT
– Saturation: VDS > VGS – VT
μCoxW
iD = (vGS - VT )2
2L
– Triode or linear or ohmic or non-saturation: VDS <= VGS
– VT i = μCoxW ((v - V )V - VDS )
2
D GS T DS 2
L
13. With channel length modulation
μCoxW
iD = (vGS - VT ) ( 1 + λVDS )
2
2L
VT = VT 0 + γ ( 2|φ f | + |v BS| - 2|φ f | )
μCoxW W
β = = K'
L L
15. CBD and CBS include both the diffusion-bulk
junction capacitance as well as the side wall
junction capacitance. They are highly nonlinear
in bias voltages.
C4 is the capacitance between the channel and
the bulk. It is highly nonlinear and depends on
the operation of the device. C4 is not
measurable from terminals.
24. High Frequency Figures of Merit ωT
• AC current source input to G
• AC short S, D, B to gnd
• Measure AC drain current output
• Calculate current gain
• Find frequency at which current gain = 1.
• Ignore rs and rd, Cbs, Cbd, gds, gbs, gbd all have
zero voltage drop and hence zero current
• Vgs = Iin /jw(Cgs+Cgb+Cgd) ≈ Iin /jwCgs
• Io = − (gm − jw Cgd)Vgs ≈ − gmVgs
• |Io/Iin| ≈ gm/wCgs
25. • At ωT, current gain =1
• ωT ≈ gm/(Cgs+Cgd)≈ gm/Cgs
• or
W
gm
µ nCox (VGS − VT ) 3µ (V − V )
ωT ≈ ≈ L = n GS2 T
C gs 2 2L
WLCox
3
gm µ n (VGS − VT )
ωT = ≈
C gs + C gd L2
26. High Frequency Figures of Merit ωmax
• AC current source input to G
• AC short S, D, B to gnd
• Measure AC power into the gate
• Assume complex conjugate load
• Compute max power delivered by the transistor
• Find maximum power gain
• Find frequency at which power gain = 1.
28. BSIM models
• Non-uniform charge density
• Band bending due to non-uniform gate voltage
• Non-uniform threshold voltage
– Non-uniform channel doping, x, y, z
– Short channel effects
• Charge sharing
• Drain-induced barrier lowering (DIBL)
– Narrow channel effects
– Temperature dependence
• Mobility change due to temp, field (x, y)
• Source drain, gate, bulk resistances
29. “Short Channel” Effects
• VTH decreases for small L
– Large offset for diff pairs with small L
• Mobility reduction:
– Velocity saturation
– Vertical field (small tox=6.5nm)
– Reduced gm: increases slower than root-ID
30. Threshold Voltage VTH
• Strong function of L
– Use long channel for VTH matching
– But this increases cap and decreases speed
• Process variations
– Run-to-run
– How to characterize?
– Slow/nominal/fast
– Both worst-case & optimistic
31. Effect of Velocity Saturation
• Velocity ≈ mobility * field
• Field reaches maximum Emax
– (Vgs-Vt)/L reaches ESAT
• gm become saturated:
– gm ≈ ½µnCoxW*ESAT
• But Cgs still 2/3 WL Cox
• ωT ≈ gm/Cgs = ¾ µnESAT /L
• No longer ~ 1/L^2
32. Threshold Reduction
• When channel is short, effect of Vd extends to S
• Cause barrier to drop, i.e. Vth to drop
• Greatly affects sub-threshold current: 26 mV Vth
drop current * e
• 100~200 mV Vth drop due to Vd not uncommon
100s or 1000 times current increase
• Use lower density active near gate but higher
density for contacts
33. Other effects
• Temperature variation
• Normal-Field Mobility Degradation
• Substrate current
– Very nonlinear in Vd
• Drain to source leakage current at Vgs=0
– Big concern for static power
• Gate leakage currents
– Hot electron
– Tunneling
– Very nonlineary
• Transit Time Effects
34. Consequences for Design
• SPICE (HSPICE or Spectre)
– BSIM3, BSIM4 models
– Accurate but inappropriate for hand analysis
– Verification (& optimization)
• Design:
– Small signal parameter design space:
• g m, C L (speed, noise)
• gm/ID, ID (power, output range, speed)
• Av0= gmro (gain)
– Device geometries from SPICE (table, graph);
– may require iteration (e.g. CGS)
35. Intrinsic voltage gain of MOSFET
Sweep V1
Measure vgs
Intrinsic voltage gain = gm/go = ∆vds/∆vgs for constant Id
36. Electronic Noise
• Noise phenomena
• Device noise models
• Representation of noise (2-ports):
– Motivation
– Output spectral density
– Input equivalent spectral density
– Noise figure
– Sampling noise (“kT/C noise”)
• SNR versus Bits
• Noise versus Power Dissipation
– Dynamic range
– Minimum detectable signal
37. Noise in Devices and Circuits
•Noise is any unwanted excitation of a circuit, any
input that is not an information-bearing signal.
• External noise: Unintended coupling with other
parts of the physical world; in principle, can be
virtually eliminated by careful design.
• Intrinsic noise: Unpredictable microscopic events
inherent in the device/circuit; can be reduced, but
never eliminated.
•Noise is especially important to consider when
designing low-power systems because the signal
levels (typically voltages or currents) are small.
38. Noise vs random process variations
• random process variations
– Variations from one device to another
– For any device, it is fixed after fabrication
• Noise
– Unpredictable variations during operation
– Unknown after fabrication
– Remains unknown after measurement during
operation
– May change with environment
41. Signal and noise power:
x(t ) = s (t ) + n(t )
1 T 2
Ps = ∫ s (t ) dt , S (rms) = Srms = Ps
T 0
1 T 2
Pn = ∫ n (t ) dt , N (rms ) = N rms = Pn
T 0
42. Physical interpretation
If we apply a signal (or noise) as a voltage
source across a one Ohm resistor, the power
delivered by the source is equal to the signal
power.
Signal power can be viewer as a measure of
normalized power.
power
43. Signal to noise ratio
Ps S rms
SNR = 10 log10 ( ) = 20 log10 ( )
Pn N rms
SNR = 0 dB when signal power = noise power
Absolute noise level in dB:
w.r.t. 1 mW of signal power
Pn
Pn in dB m = 10 log
1 mW
= 30 dB + 10 log( Pn )
44. SNR in bits
• A sine wave with magnitude 1 has power
= 1/2.
• Quantize it into N=2n equal levels between
-1 and 1 (with step size = 2/2n)
• Quantization error uniformly distributed
between +–1/2n
• Noise (quantization error) power
=1/3 (1/2n)2
• Signal to noise ratio
= 1/2 ÷ 1/3 (1/2n)2 =1.5(1/2n)2
= 1.76 + 6.02n dB or n bits
48. Frequency domain description of
noise
Given n(t) stationary, its autocorrelation is:
1 T
Rn (τ ) = lim
T → ∞ 2T
∫−T n(t )n(t + τ ) dt
The power spectral density of n(t) is:
PSDn ( f ) = S n ( f ) = F ( Rn (τ ))
+∞
Pn = ∫ PSDn ( f ) df
−∞
For real signals, PSD is even. can use single sided
spectrum: 2x positive side
+∞
Pn = ∫ PSDn ( f ) df
0
↑ single sided PSD
49. Parseval’s Theorem:
If x(t ) ⇔ X ( f )
⇓
+∞ 2 +∞ 2
∫− ∞ x(t ) dt = ∫
−∞
X ( f ) df
If x(t) stationary,
R x (τ ) ⇔ PSDx ( f )
⇓
+T 2 +∞
lim
T →∞ ∫
−T
x(t ) dt = Rx (0) = ∫
−∞
PSDx ( f ) df
53. Types of “Noise”
• “man made”
– Interference
– Supply noise
–…
– Use shielding, careful layout, isolation, …
• “intrinsic” noise
– Associated with current conduction
– “fundamental” –thermal noise
– “manufacturing process related”
– flicker noise
54. Thermal Noise
• Due to thermal excitation of charge carriers in a
conductor. It has a white spectral density and is
proportional to absolute temperature, not
dependent on bias current.
• Random fluctuations of v(t) or i(t)
• Independent of current flow
• Characterization:
– Zero mean, Gaussian pdf
– Power spectral density constant or “white” up to about
80THz
56. HW
Equivalently, we can model a real resistor with an
ideal resistor in parallel with a current noise source.
What rms value should the current source have?
Show that when two resistors are connected in
series, we can model them as ideal series resistors
in series with a single noise voltage source. What’s
the rms value of the voltage source?
Show that two parallel resistors can be modeled as
two ideal parallel resistors in parallel with a single
noise current source. What’s the rms value of the
current source?
57. Noise in Diodes
Shot noise dominant
– DC current is not continuous and smooth but
instead is a result of pulses of current caused by
the individual flow of carriers.
It depends on bias, can be modeled as a
white noise source and typically larger than
thermal noise.
− Zero mean
– Gaussian pdf
– Power spectral density flat
– Proportional to current
– Dependent on temperature
60. Flicker noise
–Kf,NMOS 6 times larger than Kf,PMOS
–Strongly process dependent
−when referred to as drain current noise, it
is inversely proportional to L2
64. Noise Calculations
1) Get small-signal model
2) Set all inputs = 0 (linear superposition)
3) Pick output vo or io
4) For each noise source vx, or ix
Calculate Hx(s) = vo(s) / vx(s) (or … io, ix)
5) Total noise at output is
6) Input Referred Noise: Fictitious noise source at
input: 2
vin ,eff = von ,T / A( s )
2 2
65. Example: CS Amplifier
VDD Von=(inRL +inMOS)/goT
RL goT = 1/RL + sCL
1
Μ1 CL
2
i
nRL = 4 k BT
RL
2
2
i
nMOS = 4 k BT g m
3
68. HW
In the previous example, if the transistor is
in triode, how would the solution change?
HW
If we include the flicker noise source, how
would that affect the computation? What
do you suggest we should modify?
HW
In the example, if RL is replaced by a PMOS
transistor in saturation, how would the
solution change? Assume appropriate bias
levels.