MIMXRT1166D ADC is 1.8V max?

[maglash64]

Hi, 

I am developing a custom board for MIMXRT1166D,

In the EVK schematic, the ADC_VREFH is attached to the 1V8 rail.

Is the max voltage on analog pins 1V8? If so then Why?

Because MIMXRT1050 and MIMXRT1060 had max ADC input voltage of 3V3.

We are interfaring with a 3V3 sensor that gives an analog output, thus this became an issue when

we began porting our product over MIMXRT1166.

Why did the max ADC voltage change from MIMXRT1050/60 to MIMXRT1160/70 ?

[maglash64 · Accepted solution]

After researching for a white, I found out in the reference manual that it is indeed possible to provide a voltage greater than VDD_ADC_VREFH (1.8V) on any of the ADC pins.

To do that one needs to set the CSCALE of the particular ADC which scales the input to the range of the specified ADC ( VREH to VREFL).