ZHCSMZ6B December 2020 – July 2022 ADC3664
PRODUCTION DATA
The ADC voltage reference can be selected using the REFBUF pin. Even though there is an internal 100 kΩ pull-up resistor to AVDD, the REFBUF pin should be set to a voltage externally and not left floating. When using a voltage divider to set the REFBUF voltage (R1 and R2 in Figure 8-42), resistor values < 5 kΩ should be used.
| REFBUF VOLTAGE | VOLTAGE REFERENCE OPTION | CLOCKING OPTION |
|---|---|---|
| > 1.7 V (Default) | External reference | Differential clock input |
| 1.2 V (1.15-1.25V) | External 1.2V input on REFBUF pin using internal gain buffer | Differential clock input |
| 0.5 - 0.7V | Internal reference | Differential clock input |
| < 0.1V | Internal reference | Single ended clock input |