Require Bulk capacitors on supply pins of nRF9160 Cellular modem.

RE: Require Bulk capacitors on supply pins of nRF9160 Cellular modem.

ketiljo — Wed, 13 Dec 2023 12:46:25 GMT

That depends on the size and how far they are, but less than 10 µF is not recommended in any case.

There's no inrush current during data transmission and your power supply should be able to handle caps of this size.

Cheers,

Ketil

RE: Require Bulk capacitors on supply pins of nRF9160 Cellular modem.

Paresh Patel — Wed, 13 Dec 2023 11:50:45 GMT

Hi Ketil Aas-Johansen,

Thanks for your reply.

You said : you have other, large caps near the VDD pins, you can can use smaller caps here.

So we can use smaller caps (lower than 47 uF) on VDD pin, right ?

Do you have any idea what minimum capacitance can we use on VDD pin ? Because of 47 uF cap, higer inrush current peak is generated during power on or data transmission.

Thanks,

Paresh

RE: Require Bulk capacitors on supply pins of nRF9160 Cellular modem.

ketiljo — Wed, 13 Dec 2023 11:30:10 GMT

The large caps are needed to provide a stable power supply when the LTE transmitter is drawing high and pulsed current. The reference design calls for 47 µF. If you have other, large caps near the VDD pins, you can can use smaller caps here.

Best regards,

Ketil Aas-Johansen