nPM1100 is not charging the battery

RE: nPM1100 is not charging the battery

Ziyao Zhou — Fri, 04 Apr 2025 10:06:03 GMT

Thank you for your information

RE: nPM1100 is not charging the battery

Tomi Koskela — Fri, 04 Apr 2025 08:21:26 GMT

nPM1100 has overcurrent protection on the buck converter. But connecting two supplies together with close to the same voltage can cause problems on either side. You could potentially add a resistor in between to avoid high current being sourced/sinked on the nPM1100 buck.

RE: nPM1100 is not charging the battery

Ziyao Zhou — Mon, 31 Mar 2025 12:39:13 GMT

I havc a debugger could be a 1.8V source, I am afraid when I connect to the debugger the 1.8V will break nPM1100 through VOUTB

RE: nPM1100 is not charging the battery

Tomi Koskela — Mon, 31 Mar 2025 05:44:20 GMT

Since the buck is configured to AUTO mode, you should be able to source the output with slightly higher voltage than the target (let's say 1.82V). But then again I'm not sure what you are trying to accomplish with this and what other rails are connected.

RE: nPM1100 is not charging the battery

Ziyao Zhou — Fri, 28 Mar 2025 12:59:26 GMT

Hi, If I connect an external 1.8V to the chip, whether the chip will be broken?

RE: nPM1100 is not charging the battery

Tomi Koskela — Fri, 28 Mar 2025 11:18:16 GMT

Yes, that is correct!

RE: nPM1100 is not charging the battery

Ziyao Zhou — Fri, 28 Mar 2025 11:11:46 GMT

Thank you for your information! I should connect one 10kOhm between NTC and GND right?

RE: nPM1100 is not charging the battery

Tomi Koskela — Fri, 28 Mar 2025 11:01:30 GMT

Hello,

It seems NTC is floating in the schematic. There should be 10kohm resistor if there is no NTC resistor on the battery pack. Having this pin floating the device detects this as battery being in very cold temperature and it will not charge.