Part Number:TPS54331
Hi TI EE：
I am using TPS54331DR as 5V to 1.2V buck convertor,and when 5V power off ,1.2V output have big ripple and 1.2V output can run to 1.6V.
My circuit as bellow:
The waveform as bellow
CH1:5V VinCH2:TPS54331DR Comp VoltageCH3:TPS54331 VsenseCH4:1.2V Vout
When 5V Vin shutdown with ripples,and 1.2V Vout also have ripple and the 1.2V Vout over shoot can as high as 1.6V.
Zoom the 1.2V Vout Over shoot waveforms as bellow :
CH1:5V Vin CH2:TPS54331DR Comp Voltage CH3:TPS54331 Vsense CH4:1.2V Vout
Please help to solve the 1.2V Vout Over shoot problem ASAP.
Thank you very much.
BR
Cheney_Sun