RESET VOLTAGE FOR NRF52840

[Nivethitha]

We have given 1.8V supply voltage for nRF52840-QIAA in our application.

The following data is given in datasheet:

1) VDD,POR VDD supply voltage needed during power-on reset. 1.75 V
2) VDD Normal voltage mode operating voltage. 1.7 to 3.6 V

If supply voltage is between 1.7V to 3.6V, how the power-on reset threshold voltage can be 1.75V? Is this typo error in datasheet.

Queries:

1) What can be the minimum reset threshold voltage if external reset IC is used for nRF52840-QIAA?

2) What is the reset threshold voltage of the module (internal POR)?

[Simonr]

Hi

1. In order to power on, you will need 1.75V. Then the normal operating voltage will be able to go down to 1.7V.

2. Then the device will likely brown out if the voltage goes below 1.7V according to the VBOR. (see table in PS 5.3.8.4 Power fail comparator in the PS).

Best regards,

Simon