tailieunhanh - Lecture Electrical Engineering: Lecture 16 - Dr. Nasim Zafar

In this chapter, you will learn about: DC current and voltage analysis, DC analysis of transistor circuits, modes of operation of a BJT Transistor, transistor characteristics. | Dr. Nasim Zafar Electronics 1 EEE 231 – BS Electrical Engineering Fall Semester – 2012 COMSATS Institute of Information Technology Virtual campus Islamabad DC Analysis of Transistor Circuits-I Lecture No: 16 Contents: DC Current and Voltage Analysis. Examples and Exercises. Nasim Zafar 2 NPN Transistor Nasim Zafar 3 Operation of an NPN Transistor: Nasim Zafar 4 Large current Modes of Operation of a BJT Transistor: Mode: B-E Junction: B-C Junction: cutoff reverse biased reverse biased Active(linear) Forward Biased Reverse Biased saturation forward biased forward biased Nasim Zafar 5 Transistor Characteristics: IB IC IE Output Circuit Input Circuit Nasim Zafar 6 DC Current and Voltage Analysis: NPN collector emitter base IB IE IC Small Current Large current + VBE - Nasim Zafar 7 PNP collector emitter base IB IE IC Small Current Large current + VBE - Nasim Zafar 8 DC Current and Voltage Analysis: DC Analysis of Transistor Circuits. Nasim Zafar 9 DC Analysis of Transistor Circuits: The DC Analysis of the transistor circuits involves solving for all (or most of) the currents and voltages in the circuit. The most important DC parameters to solve are IC and VCE. The “Q-point” of a transistor, gives the values of IC and VCE that are present in the given transistor circuit. The first step in the DC analysis, of any transistor circuit, is to solve for one of the unknown currents, IB, IC, or IE. Nasim Zafar 10 DC Analysis of Transistor Circuits: We need a set of equations – a model of the transistor – to be used in transistor circuit theory. In a basic transistor circuit, we have three terminals - collector, base and the emitter. Nasim Zafar 11 DC Analysis of Transistor Circuits: In a basic transistor circuit, we have three terminals - collector, base and emitter; and correspondingly we have: Three possible DC voltages: VBE, VCB, VCE - but only two are independent due to KVL; and Three transistor DC currents: IB, IC, IE­ - but only two . | Dr. Nasim Zafar Electronics 1 EEE 231 – BS Electrical Engineering Fall Semester – 2012 COMSATS Institute of Information Technology Virtual campus Islamabad DC Analysis of Transistor Circuits-I Lecture No: 16 Contents: DC Current and Voltage Analysis. Examples and Exercises. Nasim Zafar 2 NPN Transistor Nasim Zafar 3 Operation of an NPN Transistor: Nasim Zafar 4 Large current Modes of Operation of a BJT Transistor: Mode: B-E Junction: B-C Junction: cutoff reverse biased reverse biased Active(linear) Forward Biased Reverse Biased saturation forward biased forward biased Nasim Zafar 5 Transistor Characteristics: IB IC IE Output Circuit Input Circuit Nasim Zafar 6 DC Current and Voltage Analysis: NPN collector emitter base IB IE IC Small Current Large current + VBE - Nasim Zafar 7 PNP collector emitter base IB IE IC Small Current Large current + VBE - Nasim Zafar 8 DC Current and Voltage Analysis: DC Analysis of Transistor Circuits. Nasim Zafar 9 DC Analysis of