[i.MX1176] Is it possible to select 3.3V for ADC vref?

[kenji]

Hi Team

Is it possible to select 3.3V for ADC vref, with i.MX1176?
At maximum supply current, ADC_VREF condition seems like 3.3V.

I suppose that it will not be possible, but please tell me how use ADC_VREF 3.3V in case possible.

[gusarambula · Accepted solution]

Hello Kenji,

You are correct in that the maximum voltage for VREFH would be 1.8V typical (1.89V absolute maximum).

However, you may use the full scale of the ADC in 3.3V mode by using the Channel Scale (ADCxCMDLy[CSCALE]) feature. This allows the input voltage to be higher than the reference.

You may find more details in section 87.6.1.3 and the ADCxCMDLy register section of the i.MXRT1170 Reference Manual (link below, please note that you may need to login to download this document).

https://www.nxp.com/webapp/Download?colCode=IMXRT1170RM

I hope that this information helps. Please let me know if there’s anything else that I can do for you.

Regards,
Gustavo

[kenji]

Hi @gusarambula -san

Thank you!