(a) Draw the small signal equivalent circuit assuming that the capacitors are short circuits for the signal. (b) Derive an expression for the voltage gain. (c) Find IDQ if R = 100kΩ, Rf = 100kΩ, RD = 3kΩ, RL = 10kΩ, VDD = 20 V, Vto = 5 V, and K = 1 mA/V 2. Determine the value of gm at the Q point. (d) Is this amplifier inverting or noninverting?

This problem is AC analysis problem. DC analysis is not needed to answer the question. A) If we assume that the peak voltage of Vbe must be less than 10 mV to avoid small signal violations determine the value of Rsig if Vi has a peak amplitude of 1 V and Is = 1mA. Hint: Don't forget r!! Answer: Rsig =. B) If you did the DC analysis on this problem and calculated Vc = 50 mV and Vs = -100 mV what is the maximum amplitude of the output voltage while the circuit stays in active mode. Answer: Vo,max =, When you "verify" a mode of operation you will need to calculate all three voltages (Vc, Ve, VE for BJTS and VG, Vs, Vp for MOSFETS) and show the correct two conditions are satisfied. Assume Capacitors acts like open circuits at DC and short circuits for AC. > Assume the following: 5V o Beta = 100 O VBE = 0.7 o V: (Thermal) = 26 mV o Vr (Threshold) = 2V O VA = - o For MOSFET saturation mode: assume: lp = K(VGs-Vr)? (Assume K = 10 mA/V²). 5kn C2 01 C1 Rsig 1kn 10k Vi IIs :C3 1mA -5V

Design a common-emitter amplifier to provide a small-signal voltage gain of approximately -10. 1. Consider the circuit shown in Figure 1. Show the following calculations in your notebook: Calculate a value for Rc so that A, z –10 Calculate values for R1 and R2 so that the circuit is bias stable and near the center of the load line. (Note: Use the datasheet for the 2N5209 transistor to make your calculations more accurate). Vcc = 10 V R1 Rc Cc2 Cci RL Vs R, REj = 499 Q Figure 1: Common-emitter amplifier for part #1

4. If Vcc = 20 V, Rc is 440, R1 is 1500, R2 is 800, R3 is 6500, Re is 1000 and beta is 175; determine the cutoff and saturation values for an amplified signal, whose original value is 250 mV. Consider the minimization of the effects of r for the circuit Vcc www R3 ww www R₁ R₂ www Rc RE