Description
Problem 1: Circuit loading, filtering
Design the bandpass RC filter to achieve >20dB attenuation at 1MHz and less than 0.1dB attenuation from 1 Hz to 10 kHz
- First, ignoring loading effects, determine 3dB frequencies (f3dB,HP and f3db,LP) that meet the specifications.
- With Rs = 100Ω and RL = 10MΩ, choose R1, R2, C1, and C2 to minimize loading effects.
- Simulate the frequency response (Vo/Vs) in Ltspice and plot it together with the ideal response in MATLAB/Python.
Problem 2: Current sources, frequency response, loading
Use the circuit and variables (no values) for the following.
- Sketch the frequency response (magnitude and phase) Vout/Is for ZL → .
- Sketch the frequency response (magnitude and phase) Vout/Is together with the unloaded response (part a) for the two conditions
- ZL = CL
- ZL = RL
- Sketch the transient response of Vout for Is as a current step from 0 to Imax (ZL → ).
Problem 3: Sampling, settling, power dissipation
The clock waveform shown above is used to drive the switch open and closed (clk = 1 → switch closed, clk = 0 → switch open). Tclk is the clock period (50% duty cycle), where Tclk = 1/fclk. Vin = 1V, R = 100 Ω, and C = 10 pF
- What is the maximum clock frequency, fclk, that allows 0.1% settling precision of Vcap each period?
- Given this clock frequency, what is the average current delivered to the capacitor?
- Verify your answers to a) and b) using Ltspice. To do this using a DC source fo Vin, you need to use an initial condition (0V) on Vcap. Include any relevant plots in your submission.
- Perform an AC simulation on the circuit in Ltspice (switch closed). Relate the frequency response to the settling time and include any relevant plots.