ADS1220: Application Circuit for Impedance Bridge

Hi Antonio,

I am glad you ask. The ADS1220 datasheet does actually include an example circuit for a ratiometric Wheatstone bridge measurement in the application section.
(In case you don't leverage the internal low-side switch to power down the bridge, I would recommend to use AIN0-AIN1 as the analog inputs to measure the output signal of the bridge and then REFP0/REFN0 as the reference input pair.)

There are other ways as well on how to derive the reference voltage for the ADC, e.g. across a shunt resistor which is placed between the lower end of the bridge and GND.
Also instead of using voltage excitation of the bridge, the integrated excitation current source in ADS1220 could be used to excite the bridge.

How you detect faults (most likely a broken sense or excitation wire) in a bridge depends a little on the exact circuit implementation.
In most cases it boils down to reading a full scale output code when something is wrong.

If you care about a little more performance, then ADS124S06 would be an excellent choice.
The ADS124S06 does also offer a few more internal monitoring features to detect faults in the bridge.

We have plans to release an application note later this year around how to leverage the different integrated monitoring functions in our ADCs for sensor fault detection.
We also plan to release a sensor measurement cookbook which shows the different ways of how to measure temperature, pressure, etc. with our highly integrated ADCs.

Regards,