SBAS991 February 2021 ADC3663
The ADC366x is equipped with an on-chip reference buffer that also includes gain to generate the 1.6 V reference voltage from an external 1.2 V reference. A 10 uF and a 0.1 uF ceramic bypass capacitor (CVREF) between the VREF and REFGND pins and a 10 uF and a 0.1 uF ceramic bypass capacitor between the REFBUF and REFGND pins are recommended. Both capacitors should be placed as close to the pins as possible. The load current from the external reference is less than 100 uA.