11.1.4 Unused Inputs and Outputs
- Analog inputs:
To minimize input leakage of the measurement channel, tie unused inputs to mid-supply voltage (AVDD + AVSS) / 2 or to AVDD.
- Digital I/O:
Not all the digital I/Os may be needed to operate the ADC. Be sure not to float both used and unused digital inputs, including during power-down mode. The following is a summary of the optional digital I/Os connection:
- CS: Tie CS low to permanently enable the serial interface.
- CLKIN: Tie CLKIN to DGND to permanently operate the ADC with the internal oscillator.
- START: Tie START to DGND to control conversions by command. Tie START to DVDD to permanently free-run conversions (Continuous-conversion mode only)
- RESET: Tie RESET to DVDD if not using hardware reset. The ADC is reset at power-on. The ADC is also reset by the RESET command.
- PWDN: Tie PWDN to DVDD if not using the hardware power-down mode. The ADC can be powered down by software.
- DRDY: The functionality of the DRDY output is also provided by the dual-mode DOUT/DRDY pin. The DOUT/DRDY output is active when CS is low. Data ready is also determined by software polling. Because the conversion data are buffered, data can be read at any time without the need to synchronize to data ready.