Stuck in high current state during nRF52832 startup

RE: Stuck in high current state during nRF52832 startup

Mike Wirth — Sat, 03 Dec 2016 20:13:08 GMT

Hey, folks, Philip is having a bit of fun with us here (at me expense -- well deserved :-) Visited his shop a couple days ago and he found the problem. Great to have a second set of eyes look at the issue, especially as eagle-eyed and skilled as his. FYI, the problem was due to a confluence of factors: too close spacing of some components on the board, lack of solder mask between them (PCB vendor?), and too much solder paste applied before reflow. In any case, two separate boards reflowed with exactly the same problems: a solder bridge between DEC2 and DEC3, and a short between two other caps (one of the high-freq crystal caps and another). So case closed. Big thanks to Philip. Mike

RE: Stuck in high current state during nRF52832 startup

Philip Freidin — Sat, 03 Dec 2016 05:44:32 GMT

Hi Mike,

I thought long and hard on this, and my best guess is that you may have a short between DEC2 and DEC3.

RE: Stuck in high current state during nRF52832 startup

Mike Wirth — Thu, 01 Dec 2016 20:04:42 GMT

Correction: The one result noted above for 4ma current is bogus. Looks like that power supply went into over current protection as well. Tried a third small power supply and got ~100ma again, as well as pulling the supply voltage down to ~2.4v. Note: Looks like the chip is acting like a 2.4v zener diode. Try to raise the supply voltage above that level and the current goes up dramatically.