RE: What is the Minimum voltage our nrf52840 can read on 8bit ADC, on 10bit ADC and 12bit ADC (ADC Accuracy)

Karl Ylvisaker — Mon, 01 Feb 2021 15:25:56 GMT

Hello Rajender,

[quote user=""]I know it basic question but i need direct answer with numbers(exact voltage accuracy)[/quote]

The nRF52840 has an 12-bit SAADC that you can configure to 14 bit resolution when using oversampling.
The ENOB is still the same, at around 10.5 bits - but this also depends on your measurement configuration and noise.
You can read more about the ENOB in this ticket, and a general discussion of the SAADC's ENOB in this reply by Stefan. For a general discussion about SAADC measurement noise please see this ticket.
So, the accuracy of the SAADC is subject to your configuration, but the ENOB will always be less than the resolution due to noise.
How accurate do you need the measurements, and what range will you require?

[quote user=""]and i am very much confused to understand about adc output calculation please help me with that[/quote]

Are you here referring to the following 'Digital output' calculation?

RESULT = (V(P) – V(N)) * (GAIN/REFERENCE) * 2^{(RESOLUTION - m)}

If so, please elaborate which part of it you would like me to explain further.

Please do not hesitate to ask if anything should be unclear, or if there is anything you would like me to explain further in depth.

Best regards,
Karl