Texas Instruments recommends a 4-layer PCB with a solid ground plane, and to keep the analog and digital traces separate. Additionally, use a low-ESR capacitor for the AVDD pin and a 0.1uF capacitor for the REF pin. Route the analog input traces away from the digital traces and avoid crossing them over the analog input pins.
To optimize the ADS7887SDBVT for low-power operation, use the lowest possible clock frequency, disable the internal reference voltage, and use the power-down mode when not converting. Additionally, consider using a lower supply voltage and reducing the analog input range to minimize power consumption.
The recommended calibration procedure involves applying a known input voltage to the ADS7887SDBVT and measuring the output code. Then, calculate the gain and offset errors and store them in non-volatile memory. Repeat this process for multiple input voltages to ensure accurate conversions across the entire input range.
During power-up, wait for the internal reference voltage to settle before starting conversions. During power-down, ensure that the internal reference voltage is fully discharged before powering down the device. This can be achieved by adding a 1kΩ resistor between the REF pin and ground.
The recommended method for driving the ADS7887SDBVT's analog input pins is to use a low-impedance source, such as an op-amp, to drive the input signal. This ensures that the input signal is not attenuated and that the ADS7887SDBVT can accurately convert the input voltage.
ADS7887SDBVT datasheet
by Texas Instruments
