Regarding capacitor load on MP1658

DC-DC Power Converters
1

Hi Sir
We used MP1658 on our circuitry to generate 0.9V from 12V for powering the main chipset. an inductor with 4.7uH and 3pcs of 100uF capacitors are applied in the output. We have a few samples that there is no output and no SW signal. But when we reduce the output capacitance to 3X22uF, output becomes normal. Could you help explain this to us as why output capacitance affects booting of MP1658 and why there are only a few samples with this symptom[among 3k of products we made, only 3pcs have this problem], thanks.

2

Hi ,
Am using MP1653 IC for my application. But im facing an high ideal current issue when no load is connected at output. Can any one help me to sort out the problem ?. The following is my Schematic Circuit (Which is recommended by MPS).

MP1653 sch
MP1653 sch930×653 157 KB