Hi Ti team
we are using ADS5482 ADC in our design. our signal BW is 500khz to 20Mhz . ADC clock freq is 105Mhz(LVDS), we are running ADC on 105MSPS. We are using internal reference voltage.
But when I probed on the input pin from the multimeter its input reference pin voltage is not constant and fluctuating between 0v to 3.1V . For stable output from ADC ,its reference voltage at input voltage should be stable 3.1V. Why this is happening ?
PFB image of ADC front end input pin circuitry
PFB ADC Schematics image
PFB decoupling cap image
Please suggest some review points to fix this problem.