A brief history of electronics is given, covering vacuum tubes and semiconductor devices. Evolution of integrated circuits is described.

Principles and theorems frequently used in electronics, such as superposition, Thevenin's theorem, source transformation, and maximum power transfer, are explained along with examples.

The meaning of the sinusoidal steady state is explained. Phasors are introduced, and the relation between a time-domain quantity and the corresponding phasors is explained. Use of phasors in circuit analysis is illustrated with the help of examples.

RC and RL circuits (with a single capacitor or a single inductor) with piece-wise constant sources are discussed. The general form of voltage and current transients is derived, and several examples are considered to illustrate how the general form can be used in circuit analysis.

The current versus voltage relationship of a diode is explained, and a simple circuit model is described. Diode circuits for wave shaping and clipping are discussed, followed by peak detector, clamper, and voltage doubler circuits. Half-wave and full-wave diode rectifiers are presented along with typical examples.

The bipolar transistor is introduced. The meaning of active, saturation, and cut-off modes is explained. The relationship between β and α for a transistor is discussed. A few simple BJT circuits are presented and analysed.

The basic principle behind a BJT amplifier is presented. Biasing schemes for a BjT amplifier are illustrated with examples. Analysis of circuits with both DC and AC sources is discussed. BJT small-signal model is derived and is used to obtain the complete small-signal equivalent circuit of the common-emitter amplifier. Frequency response of a common-emitter amplifier is discussed qualitatively.

The operational amplifier (op-amp) is introduced. Input and output resistances, and gain of an op-amp are discussed. The meaning of linear and saturation regions of operation is clarified. A few basic op-amp circuit blocks, viz., the inverting and non-inverting amplifiers, buffer, and summer are discussed. Design of an amplifier with a relatively high gain is described.

The meaning of common-mode gain, differential gain, and CMRR is explained. It is shown how the difference amplifier circuit has limitations because of finite resistor tolerances. The instrumentation amplifier, which has a higher CMRR as compared to the difference amplifier, is described. Additional op-amp circuits, viz., current-to-voltage converter, integrator, and triangle-to-sine converter, are described.

Offset voltage and input bias currents of an op-amp are discussed. Their effect on circuit performance is described.

Various types of filters are introduced, and their ideal behaviour is described. Implementation of practical filters is presented, starting with passive filters and followed by op-amp filters. Construction of asymptotic Bode plots is illustrated with an example.

Several "precision" circuits using op-amps and diodes are discussed in which the diode drop (typically about 0.7 V) is effectively eliminated. Precision clipper and clamper circuits, precision rectifier circuits are described. An interesting application, viz., AM demodulation, of a precision rectifier circuit is presented.

The concepts of negative and positive feedback are discussed qualitatively. Inverting and non-inverting Schmitt trigger circuits are discussed, and their Vo versus Vi relationships are described. Waveform generation using Schmitt triggers is described.

The principle of operation of sinusoidal oscillators is described. Some examples of gain limiting networks, which are useful in limiting the amplitude of the output voltage in sinusoidal oscillators, are presented. Two specific oscillator circuits, viz., Wien bridge oscillator and phase-shift oscillator are described.

The gain versus frequency relationship of op-amp 741 is described. Using the transfer function of the 741 op-amp, the frequency response of the inverting amplifier is explained. It is pointed out that there is a trade-off in practice between amplifier gain and cut-off frequency.

Advantages of using digital circuits are described. Operation of logic gates in terms of truth tables is discussed. Commonly used boolean theorems are presented. Different ways of writing logical expressions and the use of Karnaugh maps to minimise logical expressions are discussed. It is shown that logical expressions can be implemented using only NAND gates or only NOR gates.

Commonly used combinatorial blocks, viz., half and full adders, multiplexers, demultiplexers, encoders, decoders, are described, and their functionality is explained with the help of examples. The use of multiplexers in implementation of logical functions is described.

Sequential circuits are introduced. To begin with, the NAND and NOR latches are described, and using these ideas, edge-triggered flip-flops are introduced. In particular, the operation of the master-slave JK flip-flop is considered in detail. D flip-flop is then introduced. A few applications, viz., shift registers, multiplication using shift-add, and parallel-in-serial-out data transfer, are discussed.

Counters are introduced, and the meaning of the modulo number of a counter is explained. Various types of counters are discussed. A systematic approach for design of synchronous counters is described with the help of an example. Combination of counters to obtain a higher modulo number is illustrated with examples.

The internal circuit of a 555 timer is discussed. Two applications of the 555 timer, viz., monostable operation to generate a pulse of fixed duration and astable operation to generate a square wave, are described.

Applications of digital-to-analog and analog-to-digital converters are described. The weighted-resistor DAC is discussed and its limitation pointed out. It is shown that the R-2R ladder DAC addresses the limitations of the weighted-resistor DAC. Various types of ADC, viz., flash ADC, successive approximation ADC, counting ADC, dual-slope ADC, are described.