Calculate the Small Signal Voltage Gain

a) Calculate the small signal voltage gain a_v = v_o/v_i , input resistance R_i , and output resistance Ro for the circuit below. Assume the circuit is biased such that V_O = V_cc/2.

Note: since R_L -> ∞ in this example, the approximation r_o >> R_L does not hold! See the textbook or posting "Approximations" on the course web for more on this.

b) Verify your result with a circuit simulator. Submit a printout of the schematic diagram(or netlist), the output from the operating point analysis (mark the bias point values with a red box), and the output from the DC transfer function analysis. Comment on any discrepancies in excess of 10% between your hand analysis and the simulation.

Suggestions: Model I_Bias with an ideal current source and check "models an active current source" under the advanced tab. This prevents V_o from reaching kV during the DC sweep analysis. The the LTSpice document on the course website shows an example of a DC transfer function analysis.

Use V_cc = 5V, I_Bias = 100 μA, R_E = 2 kΩ, R_L -> ∞, I_s = 1 fA, β = 100, and V_A = 100V.