Lec11 Power Amplifiers
•Download as PPTX, PDF•
1 like•496 views
This document discusses different classes of power amplifiers, including: - Class A power amplifiers, which operate linearly for 360 degrees and have an efficiency of around 25%. - Class B and AB push-pull amplifiers, which operate for more than 180 degrees but less than 360 degrees, and can have an efficiency near 79%. - Class C power amplifiers, which operate for less than 180 degrees but can have an efficiency near 100%, making them useful for applications like RF and oscillators.
Report
Share
Report
Share
Recommended
Voltage Amplifier
This document discusses building a voltage amplifier circuit with a transistor. It explains that a voltage amplifier increases a small input voltage to a higher output voltage. The circuit uses common electronic components like an NPN transistor, resistors, and capacitors. It operates by biasing the transistor to allow a small voltage change at the base to produce a larger change at the collector. The document provides the specific components needed and discusses how to select their values to achieve the desired gain without distortion.
Large Signal Amplifier
In the case of class A amplifier, we have observed that the transistor conducts for
the full cycle of the input signal i.e. the conduction angle is 180◦. Although
the transistor conducts for the full cycle of the input signal, the power conversion
efficiency is poor in class A amplifier. In addition to that, a great deal of
distortion is introduced by the nonlinearity in the dynamic transfer characteristic
of the transistor. The power conversion efficiency can be improved by biasing
the transistor at cut off point on VCE axis and a great deal of the distortion
due to nonlinearity in dynamic transfer characteristic may be eliminated by
the push-pull configuration of the transistor as discussed in next section
Power amplifiers
Power amplifiers are concerned with efficiency, maximum power capability, and impedance matching to the output device rather than small-signal factors like amplification, linearity, and gain. There are several classes of power amplifiers including Class A, B, AB, C, and D which differ based on the conduction angle of the output and location of the Q-point. Efficiency increases as the conduction angle decreases from Class A to Class B to Class C. Transformers can be used to improve efficiency and increase the output swing of Class A amplifiers. Push-pull configurations are used for Class B amplifiers to generate a full output cycle from two transistors.
267182869 large-signal-amplifiers-ppt
Power amplifiers are classified based on their operating point or quiescent point (Q point). Class A amplifiers have their Q point at the center of the load line, resulting in linear but low efficiency operation. Class B amplifiers operate with their Q point at cutoff, providing high efficiency but distorted output. Class AB reduces distortion by adding some forward bias. Class D amplifiers switch between cutoff and saturation at a high frequency for very high efficiency operation suitable for audio.
Ass2
This document summarizes a lecture on power amplifiers, including:
- Different classes of power amplifiers like Class A, B, AB, C, and D based on conduction angle.
- Circuit designs for series-fed and transformer-coupled Class A amplifiers.
- Circuit designs for Class B amplifier using complementary pairs or a Darlington pair to achieve push-pull operation.
- Considerations for efficiency and maximum output power of different classes.
Power amplifiers
This presentation introduces us to Power amplifiers topic introduced to us in engineering.
It contains the classification of Power-amps and its uses.
Comparison of A, B & C Power Amplifiers
This document describes three classes of transistor amplifier operation: Class A, B, and C.
Class A operation has one device conducting over the entire AC cycle with a conduction angle of 360 degrees. Class B has two devices each conducting for half the cycle with a conduction angle of 180 degrees. Class C has very brief conduction over a small portion of the cycle with a conduction angle less than 180 degrees.
Class A has the highest linearity and lowest distortion but also the lowest maximum efficiency of 25%. Class B has a higher maximum efficiency of 78.5% while Class C can reach 100% efficiency but has the poorest linearity and highest distortion.
Class b amplifier
This document discusses Class B amplifiers. It explains that Class B amplifiers use two transistors to conduct for alternating half cycles of the input signal, improving efficiency over Class A amplifiers. The theoretical maximum efficiency of a Class B amplifier is 78.5%. Circuit diagrams of common-collector and push-pull Class B amplifier configurations are presented, along with their input/output waveforms and operating principles. Distortion caused by crossover regions when the input signal is low is also discussed.
Recommended
Voltage Amplifier
This document discusses building a voltage amplifier circuit with a transistor. It explains that a voltage amplifier increases a small input voltage to a higher output voltage. The circuit uses common electronic components like an NPN transistor, resistors, and capacitors. It operates by biasing the transistor to allow a small voltage change at the base to produce a larger change at the collector. The document provides the specific components needed and discusses how to select their values to achieve the desired gain without distortion.
Large Signal Amplifier
In the case of class A amplifier, we have observed that the transistor conducts for
the full cycle of the input signal i.e. the conduction angle is 180◦. Although
the transistor conducts for the full cycle of the input signal, the power conversion
efficiency is poor in class A amplifier. In addition to that, a great deal of
distortion is introduced by the nonlinearity in the dynamic transfer characteristic
of the transistor. The power conversion efficiency can be improved by biasing
the transistor at cut off point on VCE axis and a great deal of the distortion
due to nonlinearity in dynamic transfer characteristic may be eliminated by
the push-pull configuration of the transistor as discussed in next section
Power amplifiers
Power amplifiers are concerned with efficiency, maximum power capability, and impedance matching to the output device rather than small-signal factors like amplification, linearity, and gain. There are several classes of power amplifiers including Class A, B, AB, C, and D which differ based on the conduction angle of the output and location of the Q-point. Efficiency increases as the conduction angle decreases from Class A to Class B to Class C. Transformers can be used to improve efficiency and increase the output swing of Class A amplifiers. Push-pull configurations are used for Class B amplifiers to generate a full output cycle from two transistors.
267182869 large-signal-amplifiers-ppt
Power amplifiers are classified based on their operating point or quiescent point (Q point). Class A amplifiers have their Q point at the center of the load line, resulting in linear but low efficiency operation. Class B amplifiers operate with their Q point at cutoff, providing high efficiency but distorted output. Class AB reduces distortion by adding some forward bias. Class D amplifiers switch between cutoff and saturation at a high frequency for very high efficiency operation suitable for audio.
Ass2
This document summarizes a lecture on power amplifiers, including:
- Different classes of power amplifiers like Class A, B, AB, C, and D based on conduction angle.
- Circuit designs for series-fed and transformer-coupled Class A amplifiers.
- Circuit designs for Class B amplifier using complementary pairs or a Darlington pair to achieve push-pull operation.
- Considerations for efficiency and maximum output power of different classes.
Power amplifiers
This presentation introduces us to Power amplifiers topic introduced to us in engineering.
It contains the classification of Power-amps and its uses.
Comparison of A, B & C Power Amplifiers
This document describes three classes of transistor amplifier operation: Class A, B, and C.
Class A operation has one device conducting over the entire AC cycle with a conduction angle of 360 degrees. Class B has two devices each conducting for half the cycle with a conduction angle of 180 degrees. Class C has very brief conduction over a small portion of the cycle with a conduction angle less than 180 degrees.
Class A has the highest linearity and lowest distortion but also the lowest maximum efficiency of 25%. Class B has a higher maximum efficiency of 78.5% while Class C can reach 100% efficiency but has the poorest linearity and highest distortion.
Class b amplifier
This document discusses Class B amplifiers. It explains that Class B amplifiers use two transistors to conduct for alternating half cycles of the input signal, improving efficiency over Class A amplifiers. The theoretical maximum efficiency of a Class B amplifier is 78.5%. Circuit diagrams of common-collector and push-pull Class B amplifier configurations are presented, along with their input/output waveforms and operating principles. Distortion caused by crossover regions when the input signal is low is also discussed.
power amplifiers
This chapter discusses output stages and power amplifiers. It covers topics like emitter followers, push-pull stages, improved push-pull stages, large-signal considerations, efficiency, and power amplifier classes. The key goals of power amplifiers are to drive loads with high power levels and deliver large currents while experiencing small load resistances. Designing power amplifiers requires considerations of nonlinearity, efficiency, voltage and current ratings, and heat dissipation.
Power amplifire analog electronics
Power Amplifier circuits.
Output stages of types of power amplifier (class A, class B, class AB, class C, class D)
Distortions( Harmonic and Crossover).
Push-pull amplifier with and without transformer.
Complimentary symmetry and Quasi- complimentary symmetry push pull amplifier.
Class a power amplifiers
This document discusses Class A power amplifiers. Key points:
- Class A amplifiers conduct for the entire signal cycle, resulting in the lowest efficiency. The quiescent point is in the middle of the load line.
- A series fed Class A power amplifier uses a fixed bias circuit to set the operating point. The dc bias current and voltage determine the quiescent point.
- In AC operation, an input signal causes the output to vary above and below the quiescent point. The output swings until current or voltage limits are reached.
Maximum efficiency can be calculated using the maximum possible voltage and current swings given the supply voltage and load resistance. An example problem calculates input power
Power amplifiers
This document discusses different classes of power amplifiers:
- Class A amplifiers have constant current flow and output varies over the full input cycle. Maximum efficiency is 25%.
- Class B amplifiers have current flow for only half the input cycle. They require a push-pull configuration of two transistors to generate the full output cycle. Maximum efficiency is 78.5%.
- Class AB operates between classes A and B with output between 180-360 degrees.
- Class C has output for less than half the cycle and requires a resonant load circuit. It has the highest efficiency but also the highest distortion.
Power amplifier
The document summarizes different classes of power amplifiers: Class A amplifiers conduct through the full 360 degrees of the input signal with the Q-point set in the middle of the load line. Class B amplifiers conduct through 180 degrees of the input with the Q-point at 0V. Class AB is a compromise between A and B, conducting between 180-360 degrees with the Q-point between the midpoint and cutoff. Class C conducts less than 180 degrees with the Q-point below cutoff. Class D is biased for digital signals and has high efficiency.
Power amplifier
The document summarizes different classes of power amplifiers:
- Class A amplifiers have the highest linearity and operate in the linear region of the device characteristic. They are less efficient with a maximum efficiency of 50%.
- Class B amplifiers have higher efficiency than Class A up to a maximum of 78.53% but lower linearity as they operate at or near cutoff for half of each cycle.
- The document discusses characteristics like gain, output power, efficiency, and linearity tradeoffs between different classes. It also provides equations to calculate efficiency, output power, and other parameters.
Power amplifiers
Class A amplifiers have the highest linearity because the transistor is always conducting. They are the least efficient at 30% due to continuous power loss. Class B amplifiers only conduct for half of the signal cycle, improving efficiency to 50% but introducing crossover distortion. Class AB balances efficiency and distortion by conducting more than half but less than the full cycle. Class C amplifiers have the greatest efficiency of 80% but introduce heavy distortion as they conduct for less than half of the input cycle. They are used for radio frequency amplification rather than audio.
Class AB amplifiers
Class AB amplifiers combine aspects of Class A and Class B amplifiers. They are biased so both transistors conduct for small signals like Class A for lower distortion, and for large signals only one transistor conducts at a time like Class B for higher efficiency. The circuit uses a voltage divider and diodes to bias the transistors into slight conduction even without an input signal. This overcomes crossover distortion. The output operates with the Q-point slightly above cutoff and ac cutoff at the supply voltage for Class AB operation between Class A and Class B.
L08 power amplifier (class a)
This document discusses power amplifiers classified as Class A amplifiers. It describes the basic operation of a Class A amplifier, in which the collector current is always nonzero, resulting in low maximum efficiency of 25%. It covers the DC and AC analyses of a basic common-emitter Class A amplifier and a transformer-coupled Class A amplifier. The transformer-coupled configuration allows for a higher theoretical maximum efficiency of 50% by keeping the operating point very close to the supply voltage. However, practical efficiencies are still typically less than 40% due to losses in the transformer.
Amplifier classes explained
The document discusses different classes of amplifiers, including:
- Class A amplifiers operate linearly by conducting all the time, providing low distortion but low efficiency of 30%.
- Class B amplifiers use two transistors to conduct half the waveform each, improving efficiency to 50% but causing distortion at zero crossings.
- Class AB amplifiers bias transistors slightly on to conduct more than half but less than full cycles, reducing distortion without large efficiency losses.
- Other classes like D, F, G aim to further improve efficiency through switching or multiple power supplies, with some able to reach near 100% efficiency.
L08 power amplifier (class a)
This document discusses power amplifiers and class A amplifiers. It describes how class A amplifiers have low efficiency since the collector current is always nonzero, even with no input signal. It then discusses transformer-coupled class A amplifiers, how they use a transformer to couple the output to the load, providing DC isolation. This increases their efficiency over standard RC-coupled class A amplifiers.
Smart Power Amplifier
The document discusses improving the efficiency and linearity of RF power amplifiers. It proposes using a technique called outphasing which decomposes the input signal into constant amplitude signals. Additionally, it introduces using specially optimized nonlinear Q-filters to process the decomposed signals in order to improve the spectral content without sacrificing the peak-to-average power ratio. This enhances the linearity and relaxes the stringent alignment requirements of traditional outphasing amplifiers, making the technique more practical to implement. The key innovation is the use of these nonlinear Q-filters applied in the digital domain to optimize the tradeoff between spectral content and signal crest factor.
Classes of amplifiers
This Presentation Of Classes Of Amplifiers which is based on class a b ab and c amplifier by Arsalan Qureshi student of Dawood University Roll no: D-16-TE-09.
Class c amplifier_ct
Class C amplifiers have a negative voltage at the base and zero volts at the emitter, reverse biasing the base-emitter junction. The transistor only conducts a small pulse through the collector output when the signal voltage reaches 4.7V. This amplifier is efficient but has limited usefulness. It is used in radio frequency applications where the collector resonant circuit responds to an impulse by ringing at its resonant frequency, like a swing being pushed. Sharp, short collector impulses occur at the resonant frequency of the tank circuit, which continues ringing and restoring the sine wave at the output.
Op amp(operational amplifier)
This document presents an overview of operational amplifiers (op-amps). It begins with an introduction to op-amps, followed by their circuit symbol, pin diagram, important terms and equations. It describes the ideal properties of an op-amp, as well as non-ideal behaviors. Applications discussed include analog to digital converters, current sources, and zero crossing detectors. Advantages are listed as versatility and uses in various circuits. Disadvantages include limitations in power and load resistance.
The Class-D Amplifier
The document summarizes the operation of a class-D amplifier. It describes how class-D amplifiers use transistors as switches that are either fully on or fully off to achieve high efficiency. A comparator compares an audio signal to a high frequency triangle wave to generate a pulse width modulated square wave. A passive filter converts this into an analog output. Class-D amplifiers can be operated in a bridged configuration to increase output power without increasing voltage. Negative feedback is also used to improve performance.
Differential amplifier
it will be useful for engineering students in analog electronics subject. this ppt is showing basic of differential amplifier.
Class c and d
This document discusses different types of amplifier classes and their characteristics. It describes how class C amplifiers use a tuned circuit to generate a full sine wave output from a non-linear output and how class D amplifiers require a pulsed input signal. It also summarizes the advantages of class D amplifiers, including increased efficiency and reduced size, and lists some common uses like home theater and powered speakers.
L07 dc and ac load line
The document discusses DC and AC analysis of transistor amplifiers. It covers DC biasing circuits, voltage divider bias, graphical DC analysis using load lines and Q-point, AC equivalent circuits, and determining amplifier compliance from the AC load line. Key points are:
- DC load line shows all combinations of collector current (IC) and collector-emitter voltage (VCE) for given values of voltage and resistors.
- Q-point is the operating point where the load line intersects the transistor characteristic curve with no input signal.
- AC load line determines maximum output voltage compliance or swing based on saturation and cutoff points.
OpAmps
This document provides an introduction to operational amplifiers (op amps) in basic electric circuits. It discusses the history and applications of op amps, and how their internal circuitry is typically too complex for basic analysis. An ideal op amp model is presented with infinite input impedance and zero output impedance. Several examples show how to use op amps as inverting and non-inverting amplifiers, for signal summing and isolation, and to calculate output voltages. While op amps can perform useful operations, their full utility is best appreciated in later circuit and control systems courses.
Amplifiers.pdf
This document discusses different classifications of amplifiers:
1. According to frequency capabilities (audio vs. radio frequency amplifiers).
2. According to coupling methods (RC, transformer, direct coupled).
3. According to use (voltage amplifiers aim to amplify voltage with minimal current output, while power amplifiers aim to amplify power with minimal voltage change output).
It also discusses different classes of amplifiers based on their biasing point: Class A are biased in the linear region all the time, Class B are biased at cutoff so conduct for 180 degrees, Class AB are biased slightly above cutoff to conduct more than 180 degrees, and Class C are biased to conduct for much less than 180 degrees.
P2 amplifier
This document describes two classes of power amplifiers: Class A and Class B. Class A amplifiers have a conduction angle of 360 degrees, meaning the output flows for the full cycle of the input signal. They have high power dissipation and low efficiency of around 25%. Class A amplifiers are used as pre-amplifiers or for low-power audio. Class B amplifiers have a conduction angle of 180 degrees, with the output flowing for only half of the input signal cycle. They use two complementary transistors to conduct on alternating half cycles. Class B amplifiers have higher efficiency of around 78.5% and are used for applications like audio power amplifiers and DC servo motor amplifiers.
More Related Content
What's hot
power amplifiers
This chapter discusses output stages and power amplifiers. It covers topics like emitter followers, push-pull stages, improved push-pull stages, large-signal considerations, efficiency, and power amplifier classes. The key goals of power amplifiers are to drive loads with high power levels and deliver large currents while experiencing small load resistances. Designing power amplifiers requires considerations of nonlinearity, efficiency, voltage and current ratings, and heat dissipation.
Power amplifire analog electronics
Power Amplifier circuits.
Output stages of types of power amplifier (class A, class B, class AB, class C, class D)
Distortions( Harmonic and Crossover).
Push-pull amplifier with and without transformer.
Complimentary symmetry and Quasi- complimentary symmetry push pull amplifier.
Class a power amplifiers
This document discusses Class A power amplifiers. Key points:
- Class A amplifiers conduct for the entire signal cycle, resulting in the lowest efficiency. The quiescent point is in the middle of the load line.
- A series fed Class A power amplifier uses a fixed bias circuit to set the operating point. The dc bias current and voltage determine the quiescent point.
- In AC operation, an input signal causes the output to vary above and below the quiescent point. The output swings until current or voltage limits are reached.
Maximum efficiency can be calculated using the maximum possible voltage and current swings given the supply voltage and load resistance. An example problem calculates input power
Power amplifiers
This document discusses different classes of power amplifiers:
- Class A amplifiers have constant current flow and output varies over the full input cycle. Maximum efficiency is 25%.
- Class B amplifiers have current flow for only half the input cycle. They require a push-pull configuration of two transistors to generate the full output cycle. Maximum efficiency is 78.5%.
- Class AB operates between classes A and B with output between 180-360 degrees.
- Class C has output for less than half the cycle and requires a resonant load circuit. It has the highest efficiency but also the highest distortion.
Power amplifier
The document summarizes different classes of power amplifiers: Class A amplifiers conduct through the full 360 degrees of the input signal with the Q-point set in the middle of the load line. Class B amplifiers conduct through 180 degrees of the input with the Q-point at 0V. Class AB is a compromise between A and B, conducting between 180-360 degrees with the Q-point between the midpoint and cutoff. Class C conducts less than 180 degrees with the Q-point below cutoff. Class D is biased for digital signals and has high efficiency.
Power amplifier
The document summarizes different classes of power amplifiers:
- Class A amplifiers have the highest linearity and operate in the linear region of the device characteristic. They are less efficient with a maximum efficiency of 50%.
- Class B amplifiers have higher efficiency than Class A up to a maximum of 78.53% but lower linearity as they operate at or near cutoff for half of each cycle.
- The document discusses characteristics like gain, output power, efficiency, and linearity tradeoffs between different classes. It also provides equations to calculate efficiency, output power, and other parameters.
Power amplifiers
Class A amplifiers have the highest linearity because the transistor is always conducting. They are the least efficient at 30% due to continuous power loss. Class B amplifiers only conduct for half of the signal cycle, improving efficiency to 50% but introducing crossover distortion. Class AB balances efficiency and distortion by conducting more than half but less than the full cycle. Class C amplifiers have the greatest efficiency of 80% but introduce heavy distortion as they conduct for less than half of the input cycle. They are used for radio frequency amplification rather than audio.
Class AB amplifiers
Class AB amplifiers combine aspects of Class A and Class B amplifiers. They are biased so both transistors conduct for small signals like Class A for lower distortion, and for large signals only one transistor conducts at a time like Class B for higher efficiency. The circuit uses a voltage divider and diodes to bias the transistors into slight conduction even without an input signal. This overcomes crossover distortion. The output operates with the Q-point slightly above cutoff and ac cutoff at the supply voltage for Class AB operation between Class A and Class B.
L08 power amplifier (class a)
This document discusses power amplifiers classified as Class A amplifiers. It describes the basic operation of a Class A amplifier, in which the collector current is always nonzero, resulting in low maximum efficiency of 25%. It covers the DC and AC analyses of a basic common-emitter Class A amplifier and a transformer-coupled Class A amplifier. The transformer-coupled configuration allows for a higher theoretical maximum efficiency of 50% by keeping the operating point very close to the supply voltage. However, practical efficiencies are still typically less than 40% due to losses in the transformer.
Amplifier classes explained
The document discusses different classes of amplifiers, including:
- Class A amplifiers operate linearly by conducting all the time, providing low distortion but low efficiency of 30%.
- Class B amplifiers use two transistors to conduct half the waveform each, improving efficiency to 50% but causing distortion at zero crossings.
- Class AB amplifiers bias transistors slightly on to conduct more than half but less than full cycles, reducing distortion without large efficiency losses.
- Other classes like D, F, G aim to further improve efficiency through switching or multiple power supplies, with some able to reach near 100% efficiency.
L08 power amplifier (class a)
This document discusses power amplifiers and class A amplifiers. It describes how class A amplifiers have low efficiency since the collector current is always nonzero, even with no input signal. It then discusses transformer-coupled class A amplifiers, how they use a transformer to couple the output to the load, providing DC isolation. This increases their efficiency over standard RC-coupled class A amplifiers.
Smart Power Amplifier
The document discusses improving the efficiency and linearity of RF power amplifiers. It proposes using a technique called outphasing which decomposes the input signal into constant amplitude signals. Additionally, it introduces using specially optimized nonlinear Q-filters to process the decomposed signals in order to improve the spectral content without sacrificing the peak-to-average power ratio. This enhances the linearity and relaxes the stringent alignment requirements of traditional outphasing amplifiers, making the technique more practical to implement. The key innovation is the use of these nonlinear Q-filters applied in the digital domain to optimize the tradeoff between spectral content and signal crest factor.
Classes of amplifiers
This Presentation Of Classes Of Amplifiers which is based on class a b ab and c amplifier by Arsalan Qureshi student of Dawood University Roll no: D-16-TE-09.
Class c amplifier_ct
Class C amplifiers have a negative voltage at the base and zero volts at the emitter, reverse biasing the base-emitter junction. The transistor only conducts a small pulse through the collector output when the signal voltage reaches 4.7V. This amplifier is efficient but has limited usefulness. It is used in radio frequency applications where the collector resonant circuit responds to an impulse by ringing at its resonant frequency, like a swing being pushed. Sharp, short collector impulses occur at the resonant frequency of the tank circuit, which continues ringing and restoring the sine wave at the output.
Op amp(operational amplifier)
This document presents an overview of operational amplifiers (op-amps). It begins with an introduction to op-amps, followed by their circuit symbol, pin diagram, important terms and equations. It describes the ideal properties of an op-amp, as well as non-ideal behaviors. Applications discussed include analog to digital converters, current sources, and zero crossing detectors. Advantages are listed as versatility and uses in various circuits. Disadvantages include limitations in power and load resistance.
The Class-D Amplifier
The document summarizes the operation of a class-D amplifier. It describes how class-D amplifiers use transistors as switches that are either fully on or fully off to achieve high efficiency. A comparator compares an audio signal to a high frequency triangle wave to generate a pulse width modulated square wave. A passive filter converts this into an analog output. Class-D amplifiers can be operated in a bridged configuration to increase output power without increasing voltage. Negative feedback is also used to improve performance.
Differential amplifier
it will be useful for engineering students in analog electronics subject. this ppt is showing basic of differential amplifier.
Class c and d
This document discusses different types of amplifier classes and their characteristics. It describes how class C amplifiers use a tuned circuit to generate a full sine wave output from a non-linear output and how class D amplifiers require a pulsed input signal. It also summarizes the advantages of class D amplifiers, including increased efficiency and reduced size, and lists some common uses like home theater and powered speakers.
L07 dc and ac load line
The document discusses DC and AC analysis of transistor amplifiers. It covers DC biasing circuits, voltage divider bias, graphical DC analysis using load lines and Q-point, AC equivalent circuits, and determining amplifier compliance from the AC load line. Key points are:
- DC load line shows all combinations of collector current (IC) and collector-emitter voltage (VCE) for given values of voltage and resistors.
- Q-point is the operating point where the load line intersects the transistor characteristic curve with no input signal.
- AC load line determines maximum output voltage compliance or swing based on saturation and cutoff points.
OpAmps
This document provides an introduction to operational amplifiers (op amps) in basic electric circuits. It discusses the history and applications of op amps, and how their internal circuitry is typically too complex for basic analysis. An ideal op amp model is presented with infinite input impedance and zero output impedance. Several examples show how to use op amps as inverting and non-inverting amplifiers, for signal summing and isolation, and to calculate output voltages. While op amps can perform useful operations, their full utility is best appreciated in later circuit and control systems courses.
What's hot (20)
Similar to Lec11 Power Amplifiers
Amplifiers.pdf
This document discusses different classifications of amplifiers:
1. According to frequency capabilities (audio vs. radio frequency amplifiers).
2. According to coupling methods (RC, transformer, direct coupled).
3. According to use (voltage amplifiers aim to amplify voltage with minimal current output, while power amplifiers aim to amplify power with minimal voltage change output).
It also discusses different classes of amplifiers based on their biasing point: Class A are biased in the linear region all the time, Class B are biased at cutoff so conduct for 180 degrees, Class AB are biased slightly above cutoff to conduct more than 180 degrees, and Class C are biased to conduct for much less than 180 degrees.
P2 amplifier
This document describes two classes of power amplifiers: Class A and Class B. Class A amplifiers have a conduction angle of 360 degrees, meaning the output flows for the full cycle of the input signal. They have high power dissipation and low efficiency of around 25%. Class A amplifiers are used as pre-amplifiers or for low-power audio. Class B amplifiers have a conduction angle of 180 degrees, with the output flowing for only half of the input signal cycle. They use two complementary transistors to conduct on alternating half cycles. Class B amplifiers have higher efficiency of around 78.5% and are used for applications like audio power amplifiers and DC servo motor amplifiers.
Amplifier (Transformer Coupled)
The transformer coupled class A power amplifier was introduced to minimize low output power and efficiency issues of conventional class A amplifiers. It uses a transformer in the collector load circuit for impedance matching between the transistor and load. The transformer allows impedance matching by transforming the high impedance primary to a low impedance secondary connected to the load. This improves gain and efficiency over a standard class A amplifier by preventing signal power loss in resistors and providing DC isolation between stages.
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
This document discusses different classes of power amplifiers:
- Class A amplifiers operate near the center of the load line and have a conduction angle of 360 degrees but maximum efficiency of only 25%.
- Class B amplifiers have their operating point at cutoff, a conduction angle of 180 degrees, and a maximum theoretical efficiency of 78.5%.
- Class AB amplifiers have conduction angles between Class A and B to reduce crossover distortion.
- Class C amplifiers use tank circuits and have a small conduction angle below 90 degrees but maximum theoretical efficiency of 100%.
- Class D or switch-mode amplifiers use pulse-width modulation to rapidly switch transistors between cutoff and saturation for very high efficiency.
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
This document discusses different classes of power amplifiers:
- Class A amplifiers operate near the center of the load line and have a conduction angle of 360 degrees but maximum efficiency of only 25%.
- Class B amplifiers have their operating point at cutoff, a conduction angle of 180 degrees, and a maximum theoretical efficiency of 78.5%.
- Class AB amplifiers reduce crossover distortion by forward biasing transistors, providing an intermediate conduction angle between Class A and B.
- Class C amplifiers use tank circuits and have a small conduction angle below 90 degrees but maximum theoretical efficiency of 100%.
- Class D or switch-mode amplifiers use pulse-width modulation for very high efficiency power amplification.
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
This document discusses different classes of power amplifiers:
- Class A amplifiers operate near the center of the load line and have a conduction angle of 360 degrees but maximum efficiency of only 25%.
- Class B amplifiers have their operating point at cutoff, a conduction angle of 180 degrees, and a maximum theoretical efficiency of 78.5%.
- Class AB amplifiers reduce crossover distortion by forward biasing transistors, providing an intermediate conduction angle between Class A and B.
- Class C amplifiers use tank circuits and have a small conduction angle below 90 degrees but maximum theoretical efficiency of 100%.
- Class D or switch-mode amplifiers use pulse-width modulation to rapidly switch transistors between cutoff and saturation,
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Amplifiers are used in wireless communications and broadcasting, and in audio equipment of all kinds. They can be categorized as either weak-signal amplifiers or power amplifiers.
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
This document discusses different classes of power amplifiers:
- Class A amplifiers operate near the center of the load line and have a conduction angle of 360 degrees but maximum efficiency of only 25%.
- Class B amplifiers have their operating point at cutoff, a conduction angle of 180 degrees, and a maximum theoretical efficiency of 78.5%.
- Class AB amplifiers have conduction angles between Class A and B to reduce crossover distortion.
- Class C amplifiers use tank circuits and have a small conduction angle below 90 degrees but maximum theoretical efficiency of 100%.
- Class D or switch-mode amplifiers use pulse-width modulation to rapidly switch transistors between cutoff and saturation for very high efficiency.
Eedp lect 06 amplifiers_3_classes
1. Amplifiers are classified according to frequency capabilities, coupling methods, and use. They can be audio frequency amplifiers, radio frequency amplifiers, voltage amplifiers, or power amplifiers.
2. Voltage amplifiers aim to amplify input voltage with minimal current output, while power amplifiers amplify input power with minimal voltage change. Power amplifiers are needed for applications requiring high power loads.
3. Amplifiers also have different classes based on their operating point, including class A operated linearly over the entire cycle, and classes B and AB operated over more than 180 degrees but with higher efficiency. Class C amplifiers are used in radio frequency applications as they operate for less than 180 degrees with even
Transistor
1. The transistor was invented in 1947 at Bell Labs by Bardeen, Brattain, and Shockley. It uses semiconductors that can switch between conducting and insulating states to amplify signals.
2. There are two types of transistors - NPN and PNP, defined by the doping of the semiconductor material. Transistors can be configured in common base, common emitter, or common collector modes.
3. A power amplifier amplifies low-power audio signals from devices like radios or guitars to levels that can drive speakers or headphones. It uses transistors configured to handle higher currents than a typical voltage amplifier.
New Microsoft PowerPoint Presentation.pptx
There are two types of differentiator amplifiers: passive ones using only RC networks and active ones using transistors and op-amps. Active differentiators have higher output voltages and lower output resistance than passive ones. A differentiator amplifier outputs a voltage proportional to the rate of change of its input voltage. It acts as a high-pass filter, attenuating low frequencies and passing high frequencies. Differentiators are used in signal processing and instrumentation to monitor rate of change.
electronics presentation class c
This document discusses class C amplifiers. It defines an amplifier as an electronic device that increases the voltage, current, or power of a signal. It then explains that a class C amplifier is a type of amplifier where the active element (transistor) conducts for less than half of the input signal cycle, resulting in high efficiency but high distortion. The document provides a diagram of a class C amplifier circuit and explains its components and operation. It notes that class C amplifiers are commonly used in radio frequency applications due to their high efficiency.
Amplifier classes
in this slide you will learn what are classes of amplifiers and what is main difference between all classes of amplifier
and after reading this slide you will be able to explain all clases of amplifier
FundamentalsElectricCircuits.pptx
The document discusses operational amplifiers (op-amps) and how they can be used in various circuit configurations to perform mathematical operations. It introduces the basic components and characteristics of op-amps, including inverting and non-inverting amplifiers, summing amplifiers, difference amplifiers, and instrumentation amplifiers. Cascading multiple op-amp stages is also covered as a method to increase overall gain. Finally, the document shows how op-amps can be used to construct a basic digital-to-analog converter.
power amplifier -IT IS ONE OF THE AMPLIFIER WHICH CAN HANDLE LARGER SIGNALS
This document discusses different types of power amplifiers:
- Class A amplifiers conduct over the full 360 degrees of the input signal cycle and have the Q-point set in the middle of the load line, providing low distortion but low efficiency of around 25%. Transformer coupling can improve efficiency to 50%.
- Class B amplifiers conduct over 180 degrees with the Q-point at cutoff, improving efficiency but introducing crossover distortion if not implemented as a push-pull circuit.
- Class AB is a compromise between A and B, conducting between 180-360 degrees. Class C amplifiers conduct less than 180 degrees and require an LC tank circuit to generate a full sine wave output.
classesofamplifiers.pptx
The document discusses different classes of amplifiers - Class A, B, AB, and C. Class A amplifiers have the transistor always conducting, providing minimal distortion but low efficiency. Class B amplifiers use two transistors in a push-pull configuration, improving efficiency but introducing crossover distortion. Class AB amplifiers provide a compromise between Class A and B by allowing both transistors to conduct around the crossover point, eliminating distortion while gaining efficiency. Class C amplifiers have the highest efficiency but also the poorest linearity, as the output is zero for over half the input cycle, making them unsuitable for audio but used in RF amplifiers.
POWER AMPLIFIER- introduction to power amplifier.pptx
A power amplifier is the last amplifier stage that delivers power to the load. Power amplifiers are classified based on the proportion of the input cycle during which the amplifying device conducts current. Class A amplifiers conduct over the entire input cycle but have low efficiency. Class B amplifiers only amplify half of the cycle, improving efficiency but introducing distortion. Class AB is a compromise with better linearity than B. Class C has very high efficiency but is used for RF where distortion is controlled by a tuned load. Class D amplifiers use pulse-width modulation for very high efficiency.
OP AMP Applications
The document presented an overview of operational amplifiers (OP-AMPs) given by Group 12. It defined an OP-AMP as an integrated circuit that amplifies input voltage through high gain. It described OP-AMP characteristics like high open-loop gain, large input resistance, and small output resistance. Common OP-AMP applications presented included comparators, integrators, differentiators, filters, and oscillators. Circuit diagrams were provided for low-pass filters, high-pass filters, and band-pass filters built using OP-AMPs.
Electronic circuits ii unit5 part1_power_amplifiers
Electronic circuits ii unit5 part1_power_amplifiersElectronics and Communication Engineering, Institute of Road and Transport Technology
Power Amplifiers, Class A, Class B, Class C, Complementary Symmetry Amplifiers, Push-Pull Amplifiers, Class AB, Cross-over DistortionPower Amplifier EEE.pptx
The document discusses different classes of power amplifiers based on their conduction angle. A power amplifier is designed to increase the magnitude of an input signal. Common classes include Class A which conducts through the full cycle, Class B which conducts through half a cycle, Class AB which conducts between half and full cycle, and Class D which is biased for digital signals and uses switching techniques. The classes are differentiated by their conduction angle and efficiency, with higher conduction angles corresponding to higher linearity but lower efficiency.
Similar to Lec11 Power Amplifiers (20)
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
Schuler Electronics Instructor CH08 amplifiers part 3.ppt
power amplifier -IT IS ONE OF THE AMPLIFIER WHICH CAN HANDLE LARGER SIGNALS
power amplifier -IT IS ONE OF THE AMPLIFIER WHICH CAN HANDLE LARGER SIGNALS
POWER AMPLIFIER- introduction to power amplifier.pptx
POWER AMPLIFIER- introduction to power amplifier.pptx
Electronic circuits ii unit5 part1_power_amplifiers
Electronic circuits ii unit5 part1_power_amplifiers
More from Shakeel Akram
Digital logic design lab1
This document outlines the grading policy and lab manual format for a course. It provides details on how lab work will be graded, including marks for the lab manual, term project, viva, and lab performance, totaling 50% of the overall grade. It also lists the online simulator link and course links. Guidelines are given for the lab manual format, which should include the date, experiment title, objective, tools, theory, procedure, results table, precautions, and conclusion. The document provides an example lab experiment on studying the operation of a digital trainer.
Workshop practice lab 1
This document outlines the grading policy and objectives for a lab course. It will be graded based on four criteria: a lab manual (15%), term project (15%), viva (10%), and lab performance/paper (10%). The objective of the course is to develop practical skills in using electronic test equipment and the ability to construct circuits and printed circuit boards. It provides the format for the lab manual and covers several experiments on basic electronic components like resistors, capacitors, diodes, transistors, integrated circuits, LEDs, switches, and more.
Lec12 MOS Transistors
MOS transistors are voltage-controlled switches that come in two types: enhancement and depletion MOS. CMOS (complementary MOS) technology uses both pMOS and nMOS transistors arranged in pull-up and pull-down networks to construct logic gates like NOT, AND, OR, NAND, NOR, XOR, and XNOR. Circuits are also used to convert analog signals to digital (A/D conversion) and digital signals to analog (D/A conversion).
Lec10 BJT Amplifiers
This document discusses three common types of bipolar junction transistor amplifiers: common emitter, common collector, and common base. It provides details on the key characteristics of each type such as their voltage and current gains, phase shifts, and input and output resistances. Common emitter amplifiers have high voltage and current gains but are 180 degrees out of phase. Common collector amplifiers have a voltage gain of one but high current gain and no phase inversion. Common base amplifiers have high voltage gain but current gain of one.
Lec9 Transistor Bias Circuits
This document discusses establishing the proper DC operating point or Q-point for a transistor through DC biasing. It introduces DC biasing techniques like voltage divider bias that use a voltage divider circuit to set the base current, which then determines the collector current and voltage through the transistor's characteristics. This DC biasing is important to ensure the transistor operates in its linear region and not saturation or cutoff.
Lec8 Bipolar Junction Transistors
This document discusses the bipolar junction transistor (BJT) and its use as both an amplifier and a switch. As an amplifier, the BJT has a current gain β that represents the ratio of collector current Ic to base current IB. When used as a switch, the BJT operates by allowing or blocking the flow of collector current Ic depending on the voltage applied to the base terminal.
Lec7 Bipolar Junction Transistor
The document discusses the basic structure and operation of a bipolar junction transistor (BJT). It notes that a BJT has three terminals - the base, emitter, and collector. The base is lightly doped, the emitter is heavily doped, and the collector is moderately doped. It operates using the forward bias of the base-emitter junction and the reverse bias of the base-collector junction. The document also discusses transistor characteristics like DC beta and DC alpha, and how BJTs can be used as amplifiers and switches in circuits.
Lec6 Special Purpose Diode
The document discusses several electronic components. It describes how the Zener diode works in both forward and reverse directions, and can regulate voltage in the range of 1.8V to 100V through Zener breakdown at low reverse voltages typically around 5V. It explains that light emitting diodes (LEDs) use electroluminescence to emit visible light through a large exposed surface area on a semiconductor layer, with anode and cathode connections. Finally, it provides details on liquid crystal displays (LCDs), noting they combine solid and liquid states, have low power consumption and cost but require backlighting and have limited temperature ranges and reliability.
Lec5 Diode Applications
This document discusses power supply filters and regulators used to reduce noise in power supplies. It covers capacitor input filters that reduce ripple, voltage regulators that maintain a constant output voltage, diode clippers and limiters that restrict voltage levels, and clamping circuits that add a DC offset to an AC signal. Specific circuits are examined, including biased clippers and voltage divider biased clippers.
Lec4 Diode Applications
This document discusses half wave and full wave rectification in power supplies. It explains that half wave rectification only uses half of the input waveform, resulting in a lower average output voltage than full wave rectification, which uses both halves of the input waveform. The peak inverse voltage that the diode must withstand is equal to the peak input voltage. Full wave rectification using a bridge circuit provides higher output voltage than a single-diode full wave circuit, and its diodes only need to withstand the peak input voltage minus 0.7 volts.
Lec3 Introduction to Semiconductors
This document discusses diode modeling and provides an assignment on diode circuits. It covers ideal, practical, and complete diode approximations. The assignment involves determining voltages across diodes in series and parallel circuits using both ideal diode and complete diode models, accounting for diode resistances.
Lec2 Introduction to Semiconductors
This document provides an overview of semiconductors, comparing silicon and germanium, discussing their covalent bonds and energy bands. It describes how electrons and holes allow current in semiconductors, and defines intrinsic and extrinsic semiconductors, with intrinsic referring to pure silicon and germanium and extrinsic referring to doping to create N-type or P-type materials. It further explains that N-type materials have electrons as majority carriers and holes as minority carriers, while P-type is the opposite, before discussing how a PN junction diode is formed and only conducts current in one direction.
Lec1 introduction to semiconductors
This document outlines the grading policy and course outline for a semiconductor physics course. It states that the midterm and final exams will count for 25% and 50% respectively, while quizzes, assignments, a class presentation, and lab work will make up the remaining 25% of the course grade. The lab portion will be graded based on lab manuals, performance, an MCQ paper, a lab viva, and a term project. The course outline covers topics like band theory, PN junctions, transistors, amplifiers, and analog to digital conversion. Reference books and the chapter outline on atomic structure are also provided.
More from Shakeel Akram (13)
Recently uploaded
International Conference on NLP, Artificial Intelligence, Machine Learning an...
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, SerbiaLiterature Review Basics and Understanding Reference Management.pptx
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
DfMAy 2024 - key insights and contributions
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
RAT: Retrieval Augmented Thoughts Elicit Context-Aware Reasoning in Long-Hori...
RAT: Retrieval Augmented Thoughts Elicit Context-Aware Reasoning in Long-Horizon Generation
5214-1693458878915-Unit 6 2023 to 2024 academic year assignment (AutoRecovere...
Bigdata of technology
Modelagem de um CSTR com reação endotermica.pdf
Modelagem em função de transferencia. CSTR não-linear.
Low power architecture of logic gates using adiabatic techniques
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMS
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
Iron and Steel Technology Roadmap - Towards more sustainable steelmaking.pdf
Iron and Steel Technology towards Sustainable Steelmaking
ACEP Magazine edition 4th launched on 05.06.2024
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressions
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
bank management system in java and mysql report1.pdf
truth is high but higher still is truth full living
Recently uploaded (20)
International Conference on NLP, Artificial Intelligence, Machine Learning an...
International Conference on NLP, Artificial Intelligence, Machine Learning an...
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...
Literature Review Basics and Understanding Reference Management.pptx
Literature Review Basics and Understanding Reference Management.pptx
RAT: Retrieval Augmented Thoughts Elicit Context-Aware Reasoning in Long-Hori...
RAT: Retrieval Augmented Thoughts Elicit Context-Aware Reasoning in Long-Hori...
5214-1693458878915-Unit 6 2023 to 2024 academic year assignment (AutoRecovere...
5214-1693458878915-Unit 6 2023 to 2024 academic year assignment (AutoRecovere...
Low power architecture of logic gates using adiabatic techniques
Low power architecture of logic gates using adiabatic techniques
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMS
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMS
Iron and Steel Technology Roadmap - Towards more sustainable steelmaking.pdf
Iron and Steel Technology Roadmap - Towards more sustainable steelmaking.pdf
BPV-GUI-01-Guide-for-ASME-Review-Teams-(General)-10-10-2023.pdf
BPV-GUI-01-Guide-for-ASME-Review-Teams-(General)-10-10-2023.pdf
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressions
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressions
bank management system in java and mysql report1.pdf
bank management system in java and mysql report1.pdf
Manufacturing Process of molasses based distillery ppt.pptx
Manufacturing Process of molasses based distillery ppt.pptx
Lec11 Power Amplifiers
- 3. 3 CHAPTER 7
- 4. 4 POWER AMPLIFIERS • Those amplifiers that have the objective of delivering power to a load. • Rated more than 1 W • Leads to power dissipation problem • Resolved using heat sink • In case of transistor collector is critical terminal
- 5. 5 CLASS A POWER AMPLIFIER • Transistor always operates in linear region • Current flows for 360˚ • Output is the amplified replica of input signal • Large signal type • When output signal is large and approaches the limits of ac load line • Both large and small signal type comes under class A if the operate throughout in linear region • Efficiency nearly equal to 25%
- 6. 6 CLASS A POWER AMPLIFIER • Centered Q- point • Point where DC and AC load line intersects • For Class A it must be at the center
- 7. 7 CLASS A POWER AMPLIFIER • Centered Q- point
- 8. 8 CLASS A POWER AMPLIFIER • Centered Q- point
- 9. 9 CLASS B AND AB PUSH PULL POWER AMPLIFIER • Class B • Biased at cutoff so that operates for only 180˚ • Class AB • Biased to conduct slightly more than 180˚ but less than 360˚ • Advantage • Higher Power gain as efficiency is nearly equal to 79% • Dis advantage • Difficult to implement
- 10. 10 CLASS B AND AB PUSH PULL POWER AMPLIFIER • Class B operation • Biased at cutoff so that operates for only 180˚ • Q point at cutoff ICQ = 0 and VCEQ = VCE(Sat)
- 11. 11 CLASS B AND AB PUSH PULL POWER AMPLIFIER • Class AB push pull operation • Two class B amplifiers. One operate in positive cycle and other in negative • Two approaches to do that • Transformer coupling
- 12. 12 CLASS B AND AB PUSH PULL POWER AMPLIFIER • Class AB push pull operation • Two class B amplifiers. One operate in positive cycle and other in negative • Two approaches to do that • Complementary symmetry transistor
- 13. 13 CLASS C POWER AMPLIFIER • Operates for less than 180˚ of input cycle • Ideal maximum collector current is Ic(sat) and ideal minimum collector voltage is Vce(cutoff) • Provides more power gain as compared to Class A, B and AB as its efficiency in nearly equal to 100% • Out amplitude is non-linear • Used in RF applications , oscillators, modulator
- 14. 14 CLASS C POWER AMPLIFIER • Basic class C operation
- 15. 15