EC1203--ELECTRONIC CIRCUITS I Syllabus

EC1203--ELECTRONIC CIRCUITS I

TRANSISTOR BIASING

BJT - Need for biasing - Fixed bias circuit, Load line and quiescent point. Variation of quiescent point due to hFE variation within manufacturers tolerance. Stability factors. Different types of biasing circuits. Method of stabilizing the Q point to the extent possible. Advantage of Self bias (voltage divider bias) over other types of biasing. Use of Self bias circuit as a constant current circuit. Source self bias and voltage divider bias for FET. Use of JFET as a voltage variable resistor.

MIDBAND ANALYSIS OF SMALL SIGNAL AMPLIFIERS

CE, CB and CC amplifiers. Method of drawing small-signal equivalent circuit. Midband analysis of various types of single stage amplifiers to obtain gain, input impedance and output impedance. Miller-s theorem. Comparison of CB, CE and CC amplifiers and their uses. Darlington connection using similar and Complementary transistors. Methods of increasing input impedance using Darlington connection and bootstrapping. CS, CG and CD (FET) amplifiers. Multistage amplifiers. Basic emitter coupled differential amplifier circuit. Bisection theorem. Differential gain. CMRR. Use of constant current circuit to improve CMRR. Derivation of transfer characteristic, Transconductance. Use as Linear amplifier, limiter, amplitude modulator

FREQUENCY RESPONSE OF AMPLIFIERS

General shape of frequency response of amplifiers. Definition of cut off frequencies and bandwidth. Low frequency analysis of amplifiers to obtain lower cut off frequency Hybrid - pi equivalent circuit of BJTs. High frequency analysis of BJT amplifiers to obtain upper cut off frequency. High frequency equivalent circuit of FETs. High frequency analysis of FET amplifiers. Gain-bandwidth product of FETs. General expression for frequency response of multistage amplifiers. Calculation of overall upper and lower cut off frequencies of multistage amplifiers. Amplifier rise time and sag and their relation to cut off frequencies.

LARGE SIGNAL AMPLIFIERS

Classification of amplifiers (Class A, B, AB, C&D), Efficiency of class A, RC coupled and transformer-coupled power amplifiers. Class B complementary-symmetry, push-pull power amplifiers. Calculation of power output, efficiency and power dissipation. Crossover distortion and methods of eliminating it. Heat flow calculations using analogous circuit. Calculation of actual power handling capacity of transistors with and without heat sink. Heat sink design.

RECTIFIERS AND POWER SUPPLIES

Half-wave, full-wave and bridge rectifiers with resistive load. Analysis for Vdc and ripple voltage with C, CL, L-C and C-L-C filters. Voltage multipliers Zenerdiode regulator. Electronically regulated d.c power supplies. Line regulation, output resistance and temperature coefficient. Switched mode power supplies. Power control using SCR.

Reference

Text Books

1. Millman J. and Halkias .C., " Integrated Electronics ", Tata McGraw-Hill.

Reference Books

1. Robert L. Boylestad and Louis Nashelsky, 8th edn., PHI, 2002. 2. S.Salivahanan, et.al, -Electronic Devices and Circuits TMH, 1998. 3. Floyd, Electronic Devices, Sixth edition, Pearson Education, 2003. 4. I.J. Nagrath, Electronics - Analog and Digital, PHI, 1999.