ADS1174: ADS1174 single ended application

Hi Sandeep,

Thanks for your question!

I would suggest using a fully-differential amplifier (FDA) to convert your single-ended input signal to a differential signal. The ADC will always sample the differential voltage between the input pins. If you drive the converter with a single-ended input (or pseudo-differential input), you will notice a decrease in performance, specifically degraded distortion. An FDA can convert single-ended to differential and also center the input signal around a mid-supply common-mode voltage (i.e. mid-supply). This gives INP and INN the maximum swing between the ADC supply rails.

Otherwise, if you decided to use only a single-ended configuration, then INN would be tied to GND. For a pseudo-differential configuration, INN would be tied to mid-supply. The voltage on each pin must remain within the supply rails, and the differential voltage must always be less than the reference, VREF. Therefore, you can see that you cannot utilize the full-scale range of the ADC (-VREF to +VREF) unless you use a differential configuration.

Best Regards,