Is it possible to underclock my nRF51822 to save power?

[tyler]

I am working on an nRF51822 central BLE device. I am wondering if it is possible to lower the clock speed / underclock the device to save power? I know this will make it run slower, but it already is running quicker than it needs to yet it is eating up too much power.

[Turbo J]

if it is possible to lower the clock speed / underclock the device to save power

Nope. The oscillators are fixed frequency - so they can start up faster.

Modern µC are designed for low avarage power in what is called "race to idle". That means a significant power draw at high procressing speed - but only for a short active time and then switching to a low power idle state for the majority of time.

That is why you can run the NRF5x from a CR2032 (~10 mA current shorted) with a few >=10 µF reservouir capacitors.

[MartinBL]

I'm not sure if I understand the thought behind that last question, but in the nRF5 series it is actually possible to power down parts of the RAM to save power.