nRF51 dongle (pca10031) voltage regulator

[erltot]

I notice that the dongle has a 3.6V-5.5V input and a pin that sais 3.3V, I measured 3.3V on this pin so I was curious if I could run an IMU unit and an i2c/spi bridge requiring 3.3V from this pin? I could not easily find info on this, other than from the user guide pdf page 12 it sais "No reverse voltage protection on the power connections." but I am not quite sure what this mean?

[Stefan Birnir Sverrisson]

Hi

I guess "No reverse voltage protection on the power connections" means that if you connect voltage to those inputs with reverse polarity, it will most likely damage the chip, so make sure you connect plus and minus correctly if you connect an external power supply to those connectors.

The designer says the regulator should be good for 300mA, so most likely it could handle your bridge, but I can not guarantee anything, since the regulator powers both the nRF51 and the Segger chip on the nRF51-Dongle. The nRF51 consumes max 30mA, but I am not sure what the max consumption of the Segger chip is. Anyway, if your bridge consumes just a few mA, I suspect the regulator has enough margin from the max consumption of the Segger+nRF51, so that it can power your bridge.