SBAS991 February 2021 ADC3663
The ADC366x provides three different options for supplying the voltage reference to the ADC. An external 1.6 V reference can be directly connected to the VREF input; a voltage 1.2 V reference can be connected to the REFBUF input using the internal gain buffer or the internal 1.2 V reference can be enabled to generate a 1.6 V reference voltage. For best performance, the reference noise should be filtered by connecting a 10 uF and a 0.1 uF ceramic bypass capacitor to the VREF pin. The internal reference circuitry of the ADC366x is shown in Figure 8-15.