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]

Would there be a way to calculate the minimal pull up resistor value? I tried pull up values of 1M and 10M to decrease the current consumption but with these values the button is not triggered.