nRF52 ADC ENOB

[developper]

Dear All

In my application we could not use the ADC inside the nRF51822 because 10bit are under our requirements. But now with the new nRF52xxx with a built-in 12bit ADC I hoped to get the job done by the new chip. ...BUT... In the specs. there are only 9bit ENOB specified after calibration. Are those 9ENOB a "secured value", meaning: probably the ENOB is higher? Our requirements are 10ENOB+. I'm a little bit disappointed, because a ADC sold as 12bit with only 9ENOB is not that stunning.

Thanks for any replys, Tim

[Stefan Birnir Sverrisson]

Hi

what are you referring to exactly? Are you referring to the differential offset error (V_OS) of 15LSB in the SAADC electrical specification?

[developper]

Hi Stefan, not directly, I'm referring to the 21th row in the specs : 9 Enob

[Carsten Wulff]

Hi, you can get higher ENOB by enabling oversampling. At OVERSAMPLE = 4 you will get ENOB=10.5b. However, how high you can go in ENOB will be limited by the SFDR. Note that oversampling will reduce the effective sample rate.

[Stefan Birnir Sverrisson]

There is an example on this thread that enables oversampling and burst mode, see updated answer from 3.3.2016

[Stefan Birnir Sverrisson]

More recent examples here