The recommended power-up sequence is to apply VDD (analog supply) first, followed by VCC (digital supply) and then the clock signal. This ensures proper initialization of the device.
To optimize the analog input impedance, use a low-impedance source, such as a buffer amplifier, and keep the input traces as short as possible. Additionally, use a capacitor (e.g., 10nF) in parallel with the input resistor to filter out high-frequency noise.
The maximum sampling rate for the ADS7861EB is 250 kSPS (kilosamples per second) for 12-bit mode and 500 kSPS for 10-bit mode.
When not using the SPI interface, the SDO pin should be left unconnected or tied to a high-impedance state to prevent unwanted data transmission.
The REFBUF pin is an output pin that provides a buffered reference voltage (VREF) for external circuitry. It can be used to drive external components, such as a voltage reference or an analog-to-digital converter.
ADS7861EB datasheet
by Texas Instruments
