Find the AC values for the unloaded common-base amplifier. Draw the equivalent AC network. Use 25 mV/IE for re.

2. The parameters of the transistor as shown in the figure below are ß = 100 and VA = 100V. a. Find the dc voltages at the base and emitter terminals. b. Find Rc such that VCEQ = 3.5V. c. Assuming Cc and CE act as short circuits, determine the small-signal voltage gain Av = Vo/Vs. d. Repeat part (c) if a 5000 source resistor is in series with the vs signal source. V+ = +5 V Rs = 100 £2 www Us Cc RB = 10 ΚΩ I= Iausmi 0.35 mA www RC -000 V=-5 V CE

This problem is AC analysis problem. DC analysis is not needed to answer the question. A) Convert this bias circuit into a bypassed common source amplifier that has an output across a load resistor (RL). To do this you should draw three capacitors on the figure below, an input voltage source, and any resistors you think that should be added. B) In the space below the figure, Draw the hybrid n model for this amplifier circuit including all voltages and resistors. Label Vi, Vgs, and vo on the model. Assume the capacitors you add act as short circuits at AC. Be sure to include resistors R1, R2, R3, R4, and RL in the hybrid pi model. > When you "verify" a mode of operation you will need to calculate all three voltages (Vc, V8, VE for BJTS and VG, Vs, Vo 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: o Beta = 100 O VBE = 0.7 12V o V (Thermal) = 26 mV o V (Threshold) = 2V O…

c) Figure 2.3 shows the circuit diagram of a typical npn BJT common emitter amplifier. The values of RB1-30 kOhm, RB2=10.XY kOhm, Rc-3.XY kOhm, Ic=2.XY mA and Vcc=24 V. If the transistor current gain 3 = 50 determine using the full analysis and assuming VBE = 0.7 V the value of RE, hence identify the location of the Q-point (Ic, VCE, IB and VBE). Now sketch the AC circuit model of this amplifier and determine the value of the ac open circuit voltage gain Av and the ac short circuit current gain Ai. (Assume that Vth = 26 mV). Vin RB1 Cin lin RB2 -10 Rc VB RE + Vcc Vc Cout VE www li Figure 2.3 Vout Ce ¡out x=1 y=7