Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
The main contents of the chapter consist of the following: Characteristic parameters, the basic structure, configurations, common-emitter amplifier, emitter directly connects to ground, emitter connects to ground by resistor RE | Dr. Nasim Zafar Electronics 1 - EEE 231 Fall Semester – 2012 COMSATS Institute of Information Technology Virtual campus Islamabad Basic Single-Stage BJT Amplifiers Lecture No. 25 Contents: Characteristic Parameters The Basic Structure Configurations Common-Emitter Amplifier Emitter directly connects to ground Emitter connects to ground by resistor RE Common-Base Amplifier Common-Collector Amplifier(emitter follower) 2 Nasim Zafar Lecture No. 25 Reference: Single-Stage BJT Amplifier Chapter-5.7 Microelectronic Circuits Adel S. Sedra and Kenneth C. Smith. 3 Nasim Zafar Introduction The large-signal operation of the BJT amplifier, discussed in lecture 20 (Section 5.3), identifies the region over which a properly biased transistor can be operated as a linear amplifier for small signals. Methods for dc biasing the BJT were studied in lecture 22 (Section 5.5), and a detailed study of the small-signal amplifier operation was also presented (Section 5.6). We are now ready to consider practical transistor amplifiers, and we will do so in this lecture for circuits suitable for discrete-circuit fabrication. 4 Nasim Zafar Introduction (contd.) There are basically three configurations for implementing single-stage BJT amplifiers: The common-emitter The common-base and The common-collector configurations All three will be discussed in this lecture, using the same basic structure, with the same biasing arrangements. 5 Nasim Zafar Introduction (contd.) The basic circuit that we shall use, to implement the various configurations of BJT amplifiers, is shown in slide 8, Ref. Sedra-Smith (Figure 5.59). Among the various biasing schemes possible for discrete BJT amplifiers, we have selected for simplicity and effectiveness, the one employing constant-current biasing (Section 5.5). Slide 8 indicates the dc currents in all branches and the dc voltages at all nodes. 6 Nasim Zafar Introduction (contd.) We would want to select a large value for RB in order to keep the input resistance | Dr. Nasim Zafar Electronics 1 - EEE 231 Fall Semester – 2012 COMSATS Institute of Information Technology Virtual campus Islamabad Basic Single-Stage BJT Amplifiers Lecture No. 25 Contents: Characteristic Parameters The Basic Structure Configurations Common-Emitter Amplifier Emitter directly connects to ground Emitter connects to ground by resistor RE Common-Base Amplifier Common-Collector Amplifier(emitter follower) 2 Nasim Zafar Lecture No. 25 Reference: Single-Stage BJT Amplifier Chapter-5.7 Microelectronic Circuits Adel S. Sedra and Kenneth C. Smith. 3 Nasim Zafar Introduction The large-signal operation of the BJT amplifier, discussed in lecture 20 (Section 5.3), identifies the region over which a properly biased transistor can be operated as a linear amplifier for small signals. Methods for dc biasing the BJT were studied in lecture 22 (Section 5.5), and a detailed study of the small-signal amplifier operation was also presented (Section 5.6). We are now ready to consider .