Can I drive the ADS1274 in a "quasi-differential" mode, where I drive the + input single ended, and drive the -input with a Reference voltage at mid-voltage of the input range? What down-side is there to this method of input drive?
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Hi Ronald,
Thank you for your post and welcome to our forum!
I suppose to begin answering that question, I need to understand what is driving the ADS1274 and what are the common-mode and peak-to-peak characteristics of your input signal? Typically, we want the INP and INN inputs of the ADC to sit at the same common-mode voltage. If the common-mode voltage is equal to mid-supply, then we allow the signals on each input to swing in the positive and negative directions and use as much of the full-scale input range as possible.
If you are using an FDA like the THS4521, you can take a single-ended input and drive the ADS1274 inputs differentially with a common-mode voltage set by the Vocm pin, which is mid-supply if not driven to another voltage. Because the ADS1274 is an un-buffered ADC, this would be the preferred way to go. Is that something you could use?
Best Regards,