nReset Pin 0.21 for nRF52 series

[wapdrive]

Can someone please let me know the reset pin's (as in nReset pin 0.21) reset threshold voltage for the nRF52 series, specifically the nRF52810, nRF52832 and the nRF52840?

I need to know at what specific voltage level does the nRF chip consider itself reset and for how long a time is the nReset pin 0.21 to be held low?

If this could be pointed out in the pdf datasheet (product spec) this would be more helpful.

Note: I'm not interested in brown-out reset!

[Kazi Afroza Sultana]

Hello,

 The reset lines are the same as the VDD_GPIO voltage. nRESET pin is a GPIO pin https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/pin.html?cp=5_2_0_3_0#qfn48. The recommended operating condition of VDD is 1.7 to 3,6 V (https://infocenter.nordicsemi.com/topic/ps_nrf52810/recommended_op_conditions.html?cp=5_5_0_7).

nRESET is powered by supply or external supply. 

Thanks.

BR

Kazi

[wapdrive]

Hi Kazi,

Thanks for your reply.

Please refer to the green arrows in the attached image for the STM32WBA52xx BLE SoC.

Since my Vdd is3V, anything below 0.9V for more than 330nsec will be a reset condition.

Assuming P0.21 is configured in firmware not to be a GPIO but instead to be the hard reset pin for the nRF52, what's the VIL(NRST) value (reset threshold voltage) and the tNF(NRST) value (length of time )?

If this could be pointed out in the nRF52 datasheet like I've shown from the STM32WBA52xx BLE SoC datasheet, that would be nice to refer to.

Note: I'm not interested in brown-out reset!

 

[Frank Viganske]

The nReset uses a GPIO pin that is configured as input, so the same voltage levels as for GPIOs apply:

So VILis 0.3 Vdd, the same as in the example data sheet that you referred to above.

I can't help you with the minimum pulse width. It seems this value is not given in the product specifications. 

Best regards

Frank