ADS8681: ADS8681IPW ADC

Hi Divya,

There are two different operations:  conversion data reading, register writing and data reading.

For conversion data reading:  no need to program internal registers. The ADS8681 has default configuration after it's powered up, for example, +/-3Vref input range, internal reference enabled etc. You only need to follow the timing in Figure 3 in ADS8681 datasheet (You can follow the timings in Figure 4-8 if you are using different phase and more SDOs for SPI interface). A standard SPI can be used to interface with ADS8681:

1. The rising edge of CONVST/CS will initiate the conversion.    
2. The host controller can initiate a data transfer frame by bringing the CONVST/CS signal low after the end of the conversion phase, the host controller must monitor for a low-to-high transition on the RVS pin or wait for the tconv_max duration to execute this operation.
3. the host controller provides clocks on SCLK to ADC and simultaneously read the conversion data from SDO_x of ADC.

For register writing and data reading, please check the detailed information in section 7.5 in the datasheet, especially the commands in table 5 and associated note in 7.5.2. An explanation about the commands can be referred to another post on E2E:

https://e2e.ti.com/support/data-converters/f/73/t/907927

The datasheet has covered all information about these operations.

Best regards,

Dale