For the following, use the figure and the simplified NPN model from Section 2.1.1 in AoE. V_CC = 5V, C =

1F, and = 100. Use the npn Ltspice component for your simulations.

1. Select values for R_B1 and R_B2 to achieve V_B = 1V and a high-pass corner frequency (f_3dB) of 10Hz. You may ignore base current for this step.
2. Choose R_C and R_E for a gain of 10V/V (at 10kHz) and a collector current of 1mA. What is the DC value of V_CE?
3. Derive the transfer function for V_out/V_in and plot the frequency response (magnitude and phase) in MATLAB/Python.
4. Perform an AC simulation of the circuit in Ltspice. Export the frequency response data for comparison to the ideal response from Part c (plot them together). Provide reasons for any discrepancies between the two.

Problem 2: Emitter follower

Figure 2a. Emitter follower Figure 2b. Small-signal equivalent circuit

Use the Ebers-Moll model of the BJT and the figures to answer the following questions. V_CC = 5V, I_S = 10¹⁶, and = 100. When determining input/output resistances, connect a test voltage to the smallsignal circuit and determine the resistance as r = v_test/i_test. Use the npn Ltspice component for your simulations.

1. Design the biasing of the emitter follower (i.e. determine V_B and R_E) such that the collector current is 1mA and the DC level of V_out is 1V. You can do this by hand or use a MATLAB/Python script.
2. Use the small-signal model (Fig. 2b) to determine the input resistance of the circuit.
3. Use the small-signal model (Fig. 2b) to determine the output resistance of the circuit.
4. Verify your design in Ltspice and include all relevant SPICE schematics and results in your submission.