Design the circuit of the following figure to provide a differential output voltage (i.e., one taken between two collectors) of 1 V when the differential input signal is 10 mV. A current source of 1 mA and a positive supply of +5 V are available. What is the largest possible input common-mode voltage for which operation as required is possible? i.e. the transistors don't leave the Active region of operation. Assume a ≈ 1. Vcc VBI UCIO Rc Rc VC2 γει + UB2 I

Exercise 1:-

circuits by using the small signal models of the transistor. Assume the Early voltage of the transistors are infinitely large. Calculate the small-signal input and output impedances of the following Vcc R1 R1 Rout VB RE Rin R2

The small-signal model is said to be valid for voltage variations of about 5 mV. To what percentage current change does this correspond? (Consider both positive and negative signals.) What is the maximum allowable voltage signal (positive or negative) if the current change is to be limited to 10%?

The collector characteristics for a certain transistorare shown a. Find the ratio Ic/IB for VCE =10 V and IB =100,200, and 600 pA.b. The maximum allowable collector powerdissipation is 0.5 W for IB = 500 pA. Find VCE.   Hint: A reasonable approximation for the power dissipatedat the collector is the product of the collector voltage andcurrent P = IcVCE, where P is the permissible powerdissipation, Ic is the quiescent collector current, and VCE iSthe operating point collector-emitter voltage.

The DC Current Gain of a Transistor is Select one: a. Ratio of Collector Current to Base Current b. Ratio of Base Current to Collector Current c. Ratio of Emitter Current to Collector Current d. Ratio of Base Current to Emitter Current

Example 8:-

What must be the minimum power rating for the external pass transistor used with a 7815 regulator in a circuit such as that shown in Figure below? The input voltage is 30 V and the load resistance is 10 n. The maximum internal current is to be 700 mA Assume that there is no heat sink for this calculation. Keep in mind that the use of a heat sink increases the effective power rating of the transistor and you can use a lower rated transistor. Qeu VIN Re VOUT 7815

1. For the circuit in Figure 1: a) Calculate the input and output power if the input signal results in a base current of 6 mA. b) Calculate the input power dissipated by the circuit if Re is changed to 2kn. c) What maximum output power can be delivered by the circuit if Rs is changed to 2 ka? d) If the circuit is biased at its center voltage and center collector operating point, what is the input power for a maximum output power of 2W? 20V Rc = 16 2 RB 1.2 ks2 V. B = 40 100 µF Figure 1

1. For the circuit in Figure 1: a) Calculate the input and output power if the input signal results in a base current of 5 mA rms. b) Calculate the input power dissipated by the circuit if RB is changed to 1.5 kN. c) What maximum output power can be delivered by the circuit if RB is changed to 1.5 kN? d) If the circuit is biased at its center voltage and center collector operating point, what is the input power for a maximum output power of 1.5 W? +Vcc (18 V) RC -16Ω RB 1.2 k2 B - 40 100 µF