The purpose of this project is to design the feedback control for the 75 W Buck converter shown in Fig. 1 with
the following nominal parameters:
Vg = 48V, Vout = 12 V±1 %, L = 300 H, RO = 20mΩ,
CO = 100 F, RL = 3Ω, VM = 1 V, fs = 70 kHz.
Where VM is the saw-tooth PWM modulator's voltage amplitude. Reference voltage Vref = 5 V.

The design specifications are:
◼ Loop-gain cross-over frequency: fc ≥ 500Hz,
◼ Phase margin:φm≥30°,
Please design the complete feedback circuit including a PID compensator, voltage sensing, and the values of all
components except for the modulator implementation.
Your design should follow the steps below:
Step 1: (2 point)
Find steady state parameters
Step 2: (3 points)
Derive open loop small signal Gvd, Gvg and Zo, find quality factor Q, zero frequency Z, pole frequency P and
coefficient Go, etc
Step 3: (3 points)
Draw bode plots for Gvd, Gvg, Zo and loop gain T in Matlab or other software
Step 4: (3 points)
Compensator Gc(s) and voltage sensing H(s) design based on the bode plot of loop gain, modulator's gain and
the requirements of fc andφm
Step 5: (2 point)
Draw a bode plot for the loop gain with the designed compensator Gc(s) plugged in in Matlab or other software
which you prefer
Step 6: (2 point)
Compensator implementation with an operational amplifier
Step 7: (2 point)
The final circuit including a voltage sensing, an error amplifier, a compensator, and a modulator.
Step 8 (3 point, undergraduate 3 + 1 bonus point):
Close loop circuit simulation verification for your design in time domain (please show simulated time domain
response waveforms for Vout when: 1) input voltage Vg steps from 48V to 60V, 2) load current steps from 4A to 3A.