Syllabus

🔹 Unit I – Bipolar Junction Transistor (BJT)

Hours: 8 | Marks: 8

1) Types of Transistors

Two types:

• NPN Transistor

• PNP Transistor

2) Construction of Transistor

Transistor has three regions:

• Emitter (E)

• Base (B)

• Collector (C)

Symbol:

NPN and PNP symbols used

3) Working of Transistor

NPN Transistor

Current flows:

Collector → Emitter

PNP Transistor

Current flows:

Emitter → Collector

4) Transistor Configurations

Three types:

Common Base (CB)

Common Emitter (CE)

Most widely used

Common Collector (CC)

5) Transistor Characteristics

CB Mode Characteristics

Input and output characteristics

CE Mode Characteristics

More amplification

6) Current Gain

Alpha (α)

CB mode gain

Formula:

$$\alpha = \frac{I_C}{I_E}$$

Beta (β)

CE mode gain

Formula:

$$\beta = \frac{I_C}{I_B}$$

Relation between α and β

$$\beta = \frac{\alpha}{1-\alpha}$$

7) Transistor Analysis

DC Load Line

Graph showing transistor operation

Operating Point (Q point)

Working point

Regions of Operation:

Active Region

Amplification region

Cut-off Region

OFF state

Saturation Region

Fully ON state

🔹 Unit II – Transistor Biasing and Amplifier

Hours: 8 | Marks: 8

1) Stability Factor

Maintains stable operation

2) Thermal Runaway

Increase in temperature increases current

Dangerous condition

3) Voltage Divider Bias

Most stable bias method

CE Amplifier

Hybrid Parameters

Used for analysis

Low Frequency Model

Equivalent circuit

Amplifier Parameters

Input Impedance

Output Impedance

Current Gain

Voltage Gain

Power Gain

Classification of Amplifiers

Class A

Best quality

Class B

Medium efficiency

Class AB

Combination

Class C

High efficiency

🔹 Unit III – Field Effect Transistor (FET)

Hours: 7 | Marks: 7

JFET

Types:

• N-channel

• P-channel

Construction

Three terminals:

• Gate

• Source

• Drain

Working

Voltage controls current

Characteristics

Input and output characteristics

Parameters

• Drain current

• Transconductance

Difference between BJT and JFET

MOSFET

Types:

Depletion type

Enhancement type

Construction and Working

Used in IC circuits

🔹 Unit IV – Operational Amplifier (OP-AMP)

Hours: 7 | Marks: 7

Difference Amplifier

Amplifies difference

Block Diagram

Stages:

Input, Amplifier, Output

Ideal OP-AMP Characteristics

IC 741 Pin Diagram

Most common OP-AMP

Parameters

Input Bias Current

Input Offset Current

Input Offset Voltage

Open Loop Gain

Closed Loop Gain

Slew Rate

CMRR

Virtual Ground

Applications of OP-AMP

Inverting Amplifier

Non-Inverting Amplifier

Adder

Subtractor

Differentiator

Integrator

1. Explain the construction, working of CB and CE configurations of BJT and

interpret their characteristics.

2. Analyze transistor biasing circuits, stability factors, and the significance of

the operating point in amplifier design.

3. Compare the performance of different amplifier classes (A, B, AB and C)

and their applications.

4. Describe the working principles of JFETs and MOSFETs, their

characteristics, and key differences from BJTs.

5. Interpret the ideal characteristics and parameters of Op-Amps.

6. Design basic Op-Amp circuits (inverting/non-inverting amplifiers, adders,

subtractors, differentiators, and integrators).

7. Solve numerical problems related to transistor biasing, FET parameters, and

Op-Amp configurations.

8. Evaluate the role of transistors and Op-Amps in modern electronic devices

and signal-processing applications.