MEMS Oscillator

[Sven]

Hello everyone,

currently I'm working on a project with an NRF51-SoC. I want to use a MEMS Oscillator as high frequency clock source this is working very well so far. But my problem is to power down the MEMS oscillator. This little device has a Pin which shuts down the oscillator. So I guess the soft device itself can`t control the MEMS device like a "real" crystal. I guess I need to route this output enable Pin of the MEMS device to a pin of the NRF51. After that I guess I need to edit the soft device before and after a radio event. Is this the right way to use an MEMS oscillator as HFCLK and achieving the lowest power consumption (regarding clock source only)?

Best regards Sven

[run_ar]

Unfortunately we have not seen any customers successfully use mems oscillators with our radios. However, I have to admit that we do not have a lot of experience with mems oscillators. According to our HW guys you could get problems with phase noise from the MEMS oscillator beeing amplified by the radio pll, which could make radio communication unstable.

You can possible use radio notifications on the softdevice to know when to turn on/off the oscillator, but again, we don't have a lot of experience with MEMS oscillators due to the phase noise issue.