Introduction to BJT Circuits – Basic Electronics Guide
The BJT as a circuit element operates various circuits with many major and minor modifications. For the analysis of such circuits, we obtain the various conditions for proper operation of the device, and also determine the projected range of operation of the device. A detailed study of the device in a two port mode simplifies the circuit analysis of the device to a large extent. Thus, we calculate the various parameters of the devices’ performance, namely voltage gain, current gain, input impedance, and output impedance. The frequency response of the device is dealt with in detail, and a study of the various regions of operation in the frequency scale is also explained. Finally, we will discuss the various configurations of the device and take a look into the high frequency operation of the device and its performance in those regions.
Objectives of Introduction to BJT Circuits – Basic Electronics Guide
This chapter introduces biasing of BJT and bias stability. Biasing ensures that the transistor has proper gain and input impedance with undistorted output voltage when used as an amplifier. After the Q-point is established, maintaining the stability of the Q-point with respect to variations in temperature leads us to the concept of stability. Next, the small-signal low-frequency operation of the transistor is analysed. Here the circuit operates in the linear region and the calculations can be done using Kirchoff’s voltage law and Kirchoff’s circuit law. Transistor circuit models are described and designed using hybrid (h) parameters. Finally the frequency response for CE amplifier (with and without source impedance) for finding the bandwidth of the amplifier and few applications of transistors like emitter follower and Darlington pair are discussed in detail.
