Nordic Nrf52832 - nReset pull-up?

[eiadj]

Hi,

Quick questions about the Nrf52832 that I couldn't locate in the datasheet.

1) Does the nReset pin have an internal pull-up? If so, what is the value?

2) does the pull-up have to be enabled manually or is it enabled by default?

3) I don't see any external resistor on the application schematics from Nordic - is any external pull-up recommended or acceptable?

Thanks!

[Kenneth]

1. Yes, it's 13kohm

2. If pin reset is enabled in UICR, then the pull-up is enabled by default. Note however that the pin is still accessible from the MCU, so if you set the pin to output low, the chip may end up in an infinite pin reset (start-pinreset-start-pinreset...).

3. There is no problem to add external pull-up or even a capacitor, the only change will be the startup time (the time for the pin to reach logic high level).

Kenneth