I have this question.
In the MKW2xDxxx reference manual, says that there is a internal reference voltaje of 1.22V that can be used as reference for analog peripheral, with the ADCx_SC2 register we can select the reference in the bits REFSEL.
01 Alternate reference pair, that is, VALTH and V ALTL. This pair may be additional external pins or internal sources depending on the MCU configuration. See the chip configuration information for details specific to this MCU.
But in the datasheet of the MKW22 I do not see any reference to it... (perhaps I am missing something?)
Currently I am working with a custom board that uses the KW22D512 and we were couting into use this internal reference voltaje for the ADC, is there a way to use connecting it internally?, we do not have available neither the VrefH and VrefL in the custom board. (or at less in this revision).
Any help would be appreciated.
It seems the VREFOUT and therefore the internal reference voltage mentioned (VALTH, VALTL) are not available in KW2x package at all. This should be removed from Reference Manual shortly. Sorry for the inconvenience this might have caused.