Other Parts Discussed in Thread: TPS92692
Hi team,
My customer is doing input voltage ripple test on TPS92692-Q1(buck-boost), and the frequency of ripple is range from 50Hz-25kHz, Upp=4V. Now they find that when the ripple frequency increases, the input current ripple will increase badly and violate their test standard limitation, and the output current is normal. The test waveform is attached below. The yellow waveform is the input voltage, and the blue waveform is the input current, which is measured at the input supply wire.
Now I have 2 assumptions:
1. Maybe the response is too slow and make the input ripple current much higher;
2. Maybe 15uH inductor is not big enough;
Apart from this assumption, is there some other possibility we can try to make the input current ripple smaller?
And before they use 220nF connected to COMP, now we changed to 33nF connected to COMP, which is calculated by the calculator, and there is nothing better either.
Please give us some advice to solve the problem. Thanks.
Gary