Hello,
my customer has a problem about output ripple, please give me some suggestiongs how to reduce output ripple in this case.
this problem is input voltage changed from clearly voltage to big noise input voltage that will cause output ripple is bigger than before, and switching wave is not stabilize.
Please see attached file. there is two type 5V input voltage wave, type 1 is input voltage with big noise, type2 is clean. and output voltage ripple is different.
TPS54229E 5V-1.1V wave test.xlsx
And, circuit parameters is below.
Vin: 5v
Vout:1.1V
Iout:0.9A
Cin: 10uF+0.1uF
Cout: 10uF+22uF+0.1F
L:3.3uH
i konw inrease the output capaitance wil help to reduce output ripple, but in this case is not very useful by my cusomer tested result.
so, my question is,
1, in thse case, how to reduce output ripple? if reduce input voltage ripple is it will help to reduce output ripple?
2, maybe input noise breaked switching stability, in this case how to improve DCDC switching stability, whether need change LC parameter?
Look forward your reply.
Thanks and best regards
Steven