Figure 8-4 shows a board layout example for the ADS7066. Avoid crossing digital lines with the analog signal path and keep the analog input signals and the reference input signals away from noise sources.

Use 1-µF ceramic bypass capacitors in close proximity to the analog (AVDD) and digital (DVDD) power-supply pins. Avoid placing vias between the AVDD and DVDD pins and the bypass capacitors. Connect all ground pins to the ground plane using short, low-impedance paths.

Place the reference decoupling capacitor (C_REF) close to the device REF and GND pins. Avoid placing vias between the REF pin and the bypass capacitors.

The charge-kickback RC filters are placed close to the device. Among ceramic surface-mount capacitors, COG- or NPO-type ceramic capacitors provide the best capacitance precision. The type of dielectric used in COG- or NPO-type ceramic capacitors provides the most stable electrical properties over voltage, frequency, and temperature changes.