LECTURE NOTES EC6401 ELECTRONIC CIRCUITS …fmcet.in/ECE/EC6401_uw.pdfLECTURE NOTES EC6401 –...
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FATIMA MICHAEL COLLEGE OF ENGINEERING & TECHNOLOGY Madurai – Sivagangai Main Road Madurai - 625 020. [An ISO 9001:2008 Certified Institution] LECTURE NOTES EC6401 – ELECTRONIC CIRCUITS - II SEMESTER: IV / ECE Prepared by: T. SIVA KUMAR AP / ECE. SYLLABUS EC6401 ELECTRONIC CIRCUITS II L T P C 3 0 0 3 OBJECTIVES: To understand the advantages and method of analysis of feedback amplifiers. To understand the analysis and design of LC and RC oscillators, amplifiers, multivibrators, and time base generators. UNIT I FEEDBACK AMPLIFIERS 9 General Feedback Structure – Properties of negative feedback – Basic Feedback Topologies – Feedback amplifiers – Series – Shunt, Series – Series, Shunt – Shunt and Shunt – Series Feedback – Determining the Loop Gain – Stability Problem – Nyquist Plot – Effect of feedback on amplifier poles – Frequency Compensation. UNIT II OSCILLATORS 9 Classification, Barkhausen Criterion - Mechanism for start of oscillation and stabilization of amplitude, General form of an Oscillator, Analysis of LC oscillators - Hartley, Colpitts,Clapp, Franklin, Armstrong, Tuned collector oscillators, RC oscillators - phase shift –Wienbridge - Twin-T Oscillators, Frequency range of RC and LC Oscillators, Quartz Crystal Construction, Electrical equivalent circuit of Crystal, Miller and Pierce Crystal oscillators, frequency stability of oscillators. UNIT III TUNED AMPLIFIERS 9 Coil losses, unloaded and loaded Q of tank circuits, small signal tuned amplifiers - Analysis of capacitor coupled single tuned amplifier – double tuned amplifier - effect of cascading single tuned and double tuned amplifiers on bandwidth – Stagger tuned amplifiers – large signal tuned amplifiers – Class C tuned amplifier – Efficiency and applications of Class C tuned amplifier - Stability of tuned amplifiers – Neutralization - Hazeltine neutralization method. UNIT IV WAVE SHAPING AND MULTIVIBRATOR CIRCUITS 9 RC & RL Integrator and Differentiator circuits – Storage, Delay and Calculation of Transistor Switching Times – Speed-up Capaitor - Diode clippers, Diode comparator - Clampers. Collector coupled and Emitter coupled Astable multivibrator – Monostable multivibrator - Bistable multivibrators - Triggering methods for Bigtable multivibrators - Schmitt trigger circuit UNIT V BLOCKING OSCILLATORS AND TIMEBASE GENERATORS 9 UJT saw tooth waveform generator, Pulse transformers – equivalent circuit – response - applications, Blocking Oscillator – Free running blocking oscillator - Astable Blocking Oscillators with base timing – Push-pull Astable blocking oscillator with emitter timing, Frequency control using core saturation, Triggered blocking oscillator – Monostable blocking oscillator with base timing – Monostable blocking oscillator with emitter timing, Time base circuits - Voltage-Time base circuit, Current-Time base circuit – Linearization through adjustment of driving waveform. TOTAL: 45 PERIODS TEXT BOOK: 1. Sedra and Smith, “Micro Electronic Circuits”; Sixth Edition, Oxford University Press, 2011. REFERENCES: 1. Robert L. Boylestad and Louis Nasheresky, “Electronic Devices and Circuit Theory”, 10 th Edition,
Transcript of LECTURE NOTES EC6401 ELECTRONIC CIRCUITS …fmcet.in/ECE/EC6401_uw.pdfLECTURE NOTES EC6401 –...
FATIMA MICHAEL COLLEGE OF ENGINEERING & TECHNOLOGYMadurai – Sivagangai Main Road
Madurai - 625 020.[An ISO 9001:2008 Certified Institution]
LECTURE NOTES
EC6401 – ELECTRONIC CIRCUITS - II
SEMESTER: IV / ECE Prepared by: T. SIVA KUMAR AP / ECE.
SYLLABUS
EC6401 ELECTRONIC CIRCUITS II L T P C3 0 0 3
OBJECTIVES: To understand the advantages and method of analysis of feedback amplifiers. To understand the analysis and design of LC and RC oscillators, amplifiers, multivibrators, andtime base generators.
UNIT I FEEDBACK AMPLIFIERS 9General Feedback Structure – Properties of negative feedback – Basic Feedback Topologies –Feedback amplifiers – Series – Shunt, Series – Series, Shunt – Shunt and Shunt – Series Feedback –Determining the Loop Gain – Stability Problem – Nyquist Plot – Effect of feedback on amplifier poles –Frequency Compensation.
UNIT II OSCILLATORS 9Classification, Barkhausen Criterion - Mechanism for start of oscillation and stabilization of amplitude,General form of an Oscillator, Analysis of LC oscillators - Hartley, Colpitts,Clapp, Franklin, Armstrong,Tuned collector oscillators, RC oscillators - phase shift –Wienbridge - Twin-T Oscillators, Frequencyrange of RC and LC Oscillators, Quartz Crystal Construction, Electrical equivalent circuit of Crystal,Miller and Pierce Crystal oscillators, frequency stability of oscillators.
UNIT III TUNED AMPLIFIERS 9Coil losses, unloaded and loaded Q of tank circuits, small signal tuned amplifiers - Analysis ofcapacitor coupled single tuned amplifier – double tuned amplifier - effect of cascading single tunedand double tuned amplifiers on bandwidth – Stagger tuned amplifiers – large signal tuned amplifiers –Class C tuned amplifier – Efficiency and applications of Class C tuned amplifier - Stability of tunedamplifiers – Neutralization - Hazeltine neutralization method.
UNIT IV WAVE SHAPING AND MULTIVIBRATOR CIRCUITS 9RC & RL Integrator and Differentiator circuits – Storage, Delay and Calculation of Transistor SwitchingTimes – Speed-up Capaitor - Diode clippers, Diode comparator - Clampers. Collector coupled andEmitter coupled Astable multivibrator – Monostable multivibrator - Bistable multivibrators - Triggeringmethods for Bigtable multivibrators - Schmitt trigger circuit
UNIT V BLOCKING OSCILLATORS AND TIMEBASE GENERATORS 9UJT saw tooth waveform generator, Pulse transformers – equivalent circuit – response - applications,Blocking Oscillator – Free running blocking oscillator - Astable Blocking Oscillators with base timing –Push-pull Astable blocking oscillator with emitter timing, Frequency control using core saturation,Triggered blocking oscillator – Monostable blocking oscillator with base timing – Monostable blockingoscillator with emitter timing, Time base circuits - Voltage-Time base circuit, Current-Time base circuit –Linearization through adjustment of driving waveform.
TOTAL: 45 PERIODSTEXT BOOK:1. Sedra and Smith, “Micro Electronic Circuits”; Sixth Edition, Oxford University Press, 2011.REFERENCES:1. Robert L. Boylestad and Louis Nasheresky, “Electronic Devices and Circuit Theory”, 10th Edition,
Pearson Education / PHI, 20082. David A. Bell, “Electronic Devices and Circuits”, Fifth Edition, Oxford University Press, 2008.3. Millman J. and Taub H., “Pulse Digital and Switching Waveforms”, TMH, 2000.4. Millman and Halkias. C., Integrated Electronics, TMH, 2007.
Pearson Education / PHI, 20082. David A. Bell, “Electronic Devices and Circuits”, Fifth Edition, Oxford University Press, 2008.3. Millman J. and Taub H., “Pulse Digital and Switching Waveforms”, TMH, 2000.4. Millman and Halkias. C., Integrated Electronics, TMH, 2007.
Pearson Education / PHI, 20082. David A. Bell, “Electronic Devices and Circuits”, Fifth Edition, Oxford University Press, 2008.3. Millman J. and Taub H., “Pulse Digital and Switching Waveforms”, TMH, 2000.4. Millman and Halkias. C., Integrated Electronics, TMH, 2007.
Block diagramBlock diagramBlock diagram
UJT
A Unijunction transistor is a three terminal semiconductor switchingdevice.this device has a unique characteristics that when it is triggered , the emittercurrent increases regeneratively until is limited by emitter power supply theunijunction transistor can be employed in a variety of applications switching pulsegenerator saw tooth generator etc.
Construction
UJT
A Unijunction transistor is a three terminal semiconductor switchingdevice.this device has a unique characteristics that when it is triggered , the emittercurrent increases regeneratively until is limited by emitter power supply theunijunction transistor can be employed in a variety of applications switching pulsegenerator saw tooth generator etc.
Construction
UJT
A Unijunction transistor is a three terminal semiconductor switchingdevice.this device has a unique characteristics that when it is triggered , the emittercurrent increases regeneratively until is limited by emitter power supply theunijunction transistor can be employed in a variety of applications switching pulsegenerator saw tooth generator etc.
Construction
It consists of an N type silicon bar with an electrical connection on each endthe leads to these connection are called base leads. Base 1 B1 Base 2 B2 the barbetween the two bases nearer to B2 than B1. A pn junction is formed between a p typeemitter and Bar.the lead to the junction is called emitter lead E.
Operation
The device has normally B2 positive w.r.t B1
If voltage VBB is applied between B2 and B1 with emitter open. Voltage gradient isestablished along the n type bar since emitter is located nearer to B2 more than half ofVBB appears between the emitter and B1. the voltage V1 between emitter and B1establishes a reverse bias on the pn junction and the emitter current is cut off. A smallleakage current flows from B2 to emitter due to minority carriers
If a positive voltage is applied at the emitter the pn junction will remain reversebiased so long as the input voltage is less than V1 if the input voltage to the emitterexceeds V1 the pn junction becomes forward biased. under these conditions holes areinjected from the p type material into the n type bar these holes are repelled bypositive B2 terminal and they are attracted towards B1 terminal of the bar. Thisaccumulation of holes in the emitter to B1 region results in the degrees of resistancein this section of the bar the internal voltage drop from emitter to b1 is decreasedhence emitter current Ie increases as more holes are injected a condition of saturationwill eventually be reached at this point a emitter current limited by emitter powersupply only the devices is in on state. If a negative pulse is applied to the emitter, thepn junction is reverse biased and the emitter current is cut off. The device is said to beoff state.
Characteristics of UJT
The curve between Emitter voltage Ve and emitter current Ie of a UJT at a givenvoltage Vbb between the bases this is known as emitter characteristic of UJT Initiallyin the cut off region as Ve increases from zero ,slight leakage current flows fromterminal B2 to the emitter the current is due to the minority carriers in the reversebiased diode . Above a certain value of Ve forward Ie begins to flow , increasing untilthe peak voltage Vp and current Ip are reached at point P. After the peak point P anattempt to increase Ve is followed by a sudden increases in emitter current Ie withdecrease in Ve is a negative resistance portion of the curve The negative portion of thecurve lasts until the valley point V is reached with valley point voltage Vv.and valleypoint current Iv after the valley point the device is driven to saturation the differenceVp-Vv is a measure of a switching efficiency of UJT fall of Vbb decreases
Advantages of UJT
It is a Low cost device
It has excellent characteristics
It is a low-power absorbing device under normal operating conditions
TRANSFORMER EQUIVALENT CIRCUIT:The influences of a transformer’s parameters can best be understood by consideringthe equivalent circuit in below. This circuit shows a typical output pulse waveform.Assuming that this output pulse is the result of injecting an ideal rectangular inputpulse, one can see that a number of parameters are distorted. Overshoot, droop, backswing, rise time, etc. appear as unwanted signal distortion on the output pulse.Assuming the pulse transformer is properly matched and the source is delivering anideal rectangular pulse, the transformer should have low values of leakage inductanceand distributed capacitance while having a high open circuit inductance. This willlimit the deterioration of the pulse shape. Also, the factthat the source will never produce an ideal rectangular pulse adds to the problems ofdistortion.
TRANSFORMER EQUIVALENT CIRCUIT:The influences of a transformer’s parameters can best be understood by consideringthe equivalent circuit in below. This circuit shows a typical output pulse waveform.Assuming that this output pulse is the result of injecting an ideal rectangular inputpulse, one can see that a number of parameters are distorted. Overshoot, droop, backswing, rise time, etc. appear as unwanted signal distortion on the output pulse.Assuming the pulse transformer is properly matched and the source is delivering anideal rectangular pulse, the transformer should have low values of leakage inductanceand distributed capacitance while having a high open circuit inductance. This willlimit the deterioration of the pulse shape. Also, the factthat the source will never produce an ideal rectangular pulse adds to the problems ofdistortion.
TRANSFORMER EQUIVALENT CIRCUIT:The influences of a transformer’s parameters can best be understood by consideringthe equivalent circuit in below. This circuit shows a typical output pulse waveform.Assuming that this output pulse is the result of injecting an ideal rectangular inputpulse, one can see that a number of parameters are distorted. Overshoot, droop, backswing, rise time, etc. appear as unwanted signal distortion on the output pulse.Assuming the pulse transformer is properly matched and the source is delivering anideal rectangular pulse, the transformer should have low values of leakage inductanceand distributed capacitance while having a high open circuit inductance. This willlimit the deterioration of the pulse shape. Also, the factthat the source will never produce an ideal rectangular pulse adds to the problems ofdistortion.
