SBASAS3A October 2024 – July 2025 AMC0330R-Q1
PRODMIX
The reference input has an internal, 90kΩ impedance connected to GND2. Consider this impedance when driving the REFIN pin from a high-impedance source. Connect a 100nF capacitor from REFIN to GND2 to filter out high-frequency noise at the reference input. Figure 8-3 shows different options for connecting the REFIN pin.
In the first example, REFIN is shorted to VDD2. In the second example, VREFIN is derived from VDD2 through a resistive divider consisting of R1 and the internal 90kΩ input impedance. In the third example, an external voltage source drives the reference input pin.