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I have had a remarkable lack of success trying to locate information about the M0 ADC. I need to know
I want to create a voltage divider network that drops the sampled voltage down to the 0-1.0V requirement, that consumes minimum power while still giving the capacitor time to charge. The one circuit I've found consumes 20mA; if possible, I'd like to create one that reduces this to single-digit uA or better still, nA. But to do this, I need the resulting RC circuit to be able to charge the capacitor in, say, 80% of the sampling aperture time
To be more precise, I need this data for an Atmel SAMD21 chip
joe
To make the "peripheral" thingy clear: the Cortex M0 really is just the processor core. It does not provide any peripherals like an ADC. That's what's implemented by the vendor, Microchip in Your case. And that's why in this forum you might not have much success in getting an answer. The Microchip Forum might be a better place to ask specifics. But let my try and help you with your questions: The SAMD21 ADC's sampling time is controlled via its SAMPCTRL Register. You can write a register in C by simply defining a variable with its address like this, e.g:
#define ADC_SAMPCTRL *(uint32_t*)0x42004003
ADC_SAMPTCRL = your value...I'm also not entirely sure you have the right manual, though, since the ADC part starts on page 888.The manual I'm talking about can be found here: http://ww1.microchip.com/downloads/en/DeviceDoc/SAM-D21-Family-Datasheet-DS40001882C.pdf, the register I'm talking about is described on page 906.Regarding the current draw, the ADC just consumes 100nA, so it really is all about your voltage divider...Hope this helps to some extent!