Design a buck converter operating in the continuous

Question

1. Choose the design parameters

V_S = V_1N = 30V, V_out = 24V P_o = 48W, V_ramp = 6V, V_ref = 5V, I_LMIN = 0.3IL ∇V = 0.003

2. Design a buck converter operating in the continuous conduction mode at a switching frequency of 100khz and Ro = 0.1'Ω

a) Determine the values of D, R_L, K_FB, and I_C

b) Using I_LMIN and ∇V/V_out required, determine the values of L and C for this case

c) Determine the transfer function of the combined filter and load

d) Calculate the resonant frequency of the filter

e) Choose a crossover frequency where the phase reaches a minimum or crosses -180 and is atleast twice the value of the filter resonant frequency. Determine the values of the gain and phase at that location.

f) Determine the d_B values of K_FB and PMW and use them to find a d_B value of the error amplifier to get a 1dB magnitude of 0^o at the chosen crossover frequency.

g) Using the filter/load at the crossover frequency and the desired phase margin of 60°, determine the phase compensation required of the error/compensation amplifier.