Tool/software:
During load transient of 400mA to 0mA I have observed voltage overshoot approx. 5.5V (0.5V additional for approx 50ms) at output of diode.
My configuration of buck converter is shown in below snap :
The purpose of diode is to protect output from external voltage and aditional zener and diode at feedback will protect FB pin in case of overvoltage. to avoid diode loss feedback is taken after diode.
Specifications and desined parametersare :
Vin 12V Typ
Vout 5V
Iout max 400mA
L selected 100uH
Cout 40uF
Cin 20uF
RA 25K
CA 24nF
Cb 2nF
RF1 20k
RF2 6.34k
Circuit works as expected only during load step down voltage after diode has overshoot of 5.5V for approx 50ms ? Is there any way to reduce this overshoot ? does it mean controller not acting fast enough to bring down output voltage low by driving low side switch ? Is there any relation of this with ripple network ?
Thank you.
