Other Parts Discussed in Thread: ADS1292ECG-FE
Hello,
I have identified the ADS1291 24-bit ADC and it fulfills all the requirements in terms of resolution, data rate, power-consumption and interface. I don't plan to use for ECG application, but to measure a single-ended sensor output (0V-1V) (very slow changes).
However, I am surprised by the definition of single-ended input in the datasheet (SBAS502C, page 22, section 8.3.3). I expected the INN input to be tied to Ground, not to mid-supply. If I tie INN to ground, the common mode voltage is 0V according to Figure 21, but then, it is not within the range defined by equation 5 (page 24) (gain=1, VMAX_Diff = 1V).
According to the definition, INN input should be tied to a voltage (mid-supply). Can I simply connect a 1.5V voltage reference to INN and connect my sensor output (0-1V) to INP ? Would that work?
I have some experience with single-ended ADC where the negative input is tied to ground and fully differential ADC, but never come across this specific case. I'd like to have your opinion on this and know the best practices.
Thanks for your support,
Mathieu