The recommended power-up sequence is to apply VDD first, followed by AVDD, and then the digital supply (DVDD). This ensures proper operation and prevents latch-up.
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 a resistor (e.g., 1kΩ) to filter out high-frequency noise.
The maximum sampling rate for the ADS7865 is 250 kSPS (kilosamples per second) for a single channel, and 125 kSPS for multiple channels.
The ADS7865 outputs 16-bit data in two's complement format. To handle the data, use a microcontroller or FPGA to read the data and perform any necessary processing, such as scaling or averaging.
The REF pins (REFP and REFN) are used to set the analog reference voltage for the ADC. Connect a stable voltage source (e.g., 2.5V) to these pins to set the full-scale range of the ADC.
ADS7865IPBSR datasheet
by Texas Instruments
