NRF51-DK LED sink current

[Flagada15]

Hi !

There is one thing I don't understand with the led included on the NRF51-DK board. According to this thread (devzone.nordicsemi.com/.../ and the datasheet it seems that a nrf51822 can't sink more than 0.5mA by default. But on the board, if I measure the voltage at the 220ohm resistor before one active led I see a voltage of 0.73V which means a 3.3mA current. While I don't have configured any high drive on GPIO how can it be possible? Am I going to burn my NRF51822?

Thanks for your lights :)

[Stefan Birnir Sverrisson]

Hi

The nRF drive guide is on this thread

You might be able to drive higher currents than 0.5mA with standard drive, but that may result in some voltage drop on the pin below VDD voltage when driving pin with high signal. Normally, GPIO voltage should equal VDD voltage (supply voltage). The same applies when driving low signal, the pin voltage might not be 0V at high current.

[Flagada15]

Hi and thank you for your answer! It looks quite strange for me that an official nordic board accept to sink more current than normally accepted by the ship isn't it?