I was planning to make a measurement with a ratiometric IC, so I will sense both the Vcc and the Vout from the chip as shown below. For cleaning up the noise and stability I also want to add a 5V voltage regulator right before the IC. The IC is basically measuring differential pressure.
I have heard from someone that I might need to verify whether the voltage regulator has a low AC output impedance. What could be reason for such inquiry for this application and why would it matter? What is meant by AC output impedance?