RE: nRF52832 chip off but GPIO receives power, will this cause damage?

awneil — Fri, 14 Dec 2018 09:05:10 GMT

[quote userid="2115" url="~/f/nordic-q-a/41583/nrf52832-chip-off-but-gpio-receives-power-will-this-cause-damage/161814"]What will happen is that the ESD protection inside the pad will open, thus the chip will try to start up. A[/quote]

klm19 - Note that this is pretty much standard for any chip - not specific to Nordic.

RE: nRF52832 chip off but GPIO receives power, will this cause damage?

Håkon Alseth — Fri, 14 Dec 2018 08:43:15 GMT

Hi,

By applying 3.3V to a GPIO when the VDD_nRF = 0V, you are exceeding the absolute maximum ratings (for I/O pin voltage):

http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/abs_max_ratings.html?cp=2_1_0_4#abs_max_ratings

What will happen is that the ESD protection inside the pad will open, thus the chip will try to start up. A voltage divider is likely not able to provide enough current, so the voltage will likely have a saw-tooth form. I will strongly recommend that you apply VDD_NRF first, then the voltage divider.

Kind regards,

Håkon