IO Pull-up vs Pull-down consumption

[Jose Xavier]

What does consume more power, IO pull-up or IO pull-down? Didn't find information about this on the product specification.

[Stefan Birnir Sverrisson]

Hi Jose

According to nRF51822 PS v3.1 section 8.23 pullup and pulldown resistors have a typical value of 13kohm. Therefore, if you have e.g. a button that connects a certain pin to ground when pressed, and the pin is configured as input with pullup, and you have supply power of 3.0 volts for the nRF51, then the current consumption is 3/13k=230uA when the button is pressed.

[michaeld]

Thanks for you response. Yes normally this wouldn't be a problem I agree but in our product use case the button will be used very intensely. It will be pressed approximately 3 hours a day then it has quite a influence on the battery life.