Kinetis MicrocontrollersのトピックRe: Differential ADC pin as single ended

Differential ADC pin as single ended

yehuda — Tue, 26 Jun 2018 12:38:44 GMT

Hi all,

I'm planing to use the K22 MCU and according to the datasheet, the 16bit accuracy can be achieved only on the differential pin.

My question is if I can use the pins of the differential ADC as single ended ADC measured relatively to VSSA and in 16bit accuracy?

BTW, what is the resolution of the other ADC pins? according to the datasheet, there's a few options. It is programmable and up to 12bit?

10X

#kinetis-k22‌ #adc 16bit accuracy resolution‌ #differential adc‌ #single-ended‌

Re: Differential ADC pin as single ended

mjbcswitzerland — Tue, 26 Jun 2018 14:02:36 GMT

ADCs are 16 bit resolution but the maximum achievable accuracy (with longer conversion time and HW averaging) is about 14.5 bits (although can be worse depending on signal noise and power supply coupling, cross-talk, etc.).

16 bit accuracy is never possible with the ADC in the Kinetis parts (check the data sheet for maximum possible accuracy). Eg:

Regards

Mark

uTasker developer and supporter (+5'000 hours experience on +60 Kinetis derivatives in +80 product developments)
Kinetis: http://www.utasker.com/kinetis.html

Re: Differential ADC pin as single ended

yehuda — Tue, 26 Jun 2018 14:10:46 GMT

Thanks for your replay.

OK, good to know. Do you know something about the other part of my question? about using the pins of differential ADC as single ended ADC?

Re: Differential ADC pin as single ended

mjbcswitzerland — Tue, 26 Jun 2018 15:10:59 GMT

Hi Yehuda

Yes, the differential pins can be used as either differential pairs or single ended inputs (this is controlled by ADC_SC1A_DIFF in the ADCx_SC1A - set to 0 for single-ended mode of to '1' for differential input mode).
They can be referenced to VREF or VDDA.

Regards

Mark

uTasker - for more performance and faster, cheaper product development