I am using an AM3352 which has battery backup and an external 32kHz clock (not crystal) for the RTC as the time needs to be maintained during periods where the device is not powered.
For cost reasons I am looking at replacing the clock with a 32kHz crystal. I need to understand whether this means the whole processor needs to be powered to support the clock tree or whether the 32kHz oscillator is powered from the RTC power input.
If I can use an external crystal to power the RTC and crystal it would be useful to know the approximate power consumption from the RTC supply so I can size the backup battery appropriately.
Thanks
Richard
