ADC analog inputs Limited to ~ 1.6V (MK20DX128 - 32QFN)

[CG-NXP]

Running KDS project for this part.

I find that the ADC analog pins voltage protect when input exceeds 1.6V approx.

VDD ,VDDA - 3.3V

VSS,VSSA - GND

Ran 8 and 16 bit configuration - Single ended 48Mhz clk ext

Jtag/uart/PDio all work as expected.  Replaced IC same operation.  

The lower 8 bits work in both configurations

until  ADC input value reaches above 1.6V.

Is the 32QFN limited to half VDD input voltage for analog inputs and 8bit only?

Data sheet - VrefH and VrefL are connected to VDDA and VSSA respectively for this part.

[diego_charles]

Hi @CG-NXP 

I hope you are doing well!

The MK20DX128 ADC should be capable of performing 16 bit  conversions.

Could you help me with the following:

1 Code example with your ADC configuration.

2 Is the  ADC configured to work with single-ended channels?

Best regards,

Diego.