NRF52832 Schematic Review

RE: NRF52832 Schematic Review

X4ce — Thu, 30 Jan 2025 04:05:02 GMT

Yes, they have been overlooked.

RE: NRF52832 Schematic Review

calibrexnick — Wed, 29 Jan 2025 21:46:01 GMT

I discovered the cause of the malfunction: the load caps were not grounded! Grounding them resulted in the device operating as designed. Time to go spin a new board and see if I can get a refund for my EE degree...

Thanks all.

RE: NRF52832 Schematic Review

calibrexnick — Tue, 28 Jan 2025 16:26:09 GMT

Good to know, thanks. Another quick question: the ESR of my crystal is 150 max. I see this is pretty far out of tolerance - would this prevent BLE from working? I intend to swap these out but this board has already been spun and I'm not debugging

RE: NRF52832 Schematic Review

Bendik Heiskel — Tue, 28 Jan 2025 15:56:44 GMT

Hi,

C13 and C14 are only needed if you are planning on getting the device certified in Europe, as they are related to errata 138.

Since you are not using the pins, a easier fix is to just ground P0.25 and P0.26 directly, this will reduce the spurious emissions sufficiently.

Best regards,

Bendik

RE: NRF52832 Schematic Review

calibrexnick — Tue, 28 Jan 2025 15:46:42 GMT

Thanks! Do you know if C13 and C14 are critical for operation?

RE: NRF52832 Schematic Review

X4ce — Tue, 28 Jan 2025 07:14:57 GMT

A Quick observation reveals that the schematic is missing caps C13 & C14 at P0.26 & P0.25, respectively, according to the reference design.

Moreover, check VCC LDO that it can still regulate after diode's forward voltage drop.

Further, your adc VDRs comprise high impedances that may not be of much concern.

Regards

Shahid