How to solve reset problem at ESD status?

RE: How to solve reset problem at ESD status?

Devin — Wed, 26 Apr 2017 03:28:07 GMT

Thanks a lot!

RE: How to solve reset problem at ESD status?

RK — Wed, 26 Apr 2017 02:54:57 GMT

yes that's fine - or just program the device first and then solder in the cap.

I'd have thought even at 1uF you might be able to program the device v.e.r.y s..l..o..w..l..y but I suspect you'd be down to 1kHz on the clock line before the capacitor didn't shunt the signal straight to ground.

RE: How to solve reset problem at ESD status?

Devin — Mon, 24 Apr 2017 10:09:10 GMT

Hi，Thanks for your quick reply! There is a short circuit jumper between 1uF capacitor and ground. During programming, let the jumper open; After programming, short circuit the jumper to add a 1uF capacitor between SWDIO pin and ground. 1uF will be better than 1nF for filting the inferrence signal, is it OK?

RE: How to solve reset problem at ESD status?

Kenneth — Mon, 24 Apr 2017 09:43:00 GMT

Hi, the main problem with adding a 1uF is that it will prevent programming of the device, as the nRF51xxx will not be able to drive the SWDIO line during programming with such a large capacitor. The SWDIO pin is a shared pin with the nRESET pin. However using a <1nF can work, it might reduce programming speed, but it should still help to avoid pin reset due to ESD event in the final product.