Changing PGA amplifer reference on the fly under program control | Cypress Semiconductor
Changing PGA amplifer reference on the fly under program control
I am using a pga in my circuits. Most of the time I operate it at unity gain where it's input is a InsAmp referenced to AGND and the output is sent to an A to D. However, I need to get an analog signal from a ground referenced RF crystal detector in one situation. I mux PGA between the InsAmp and the crystal detector. Unfortunately, I need some gain when measuing the crystal detector, but to really get much gain without driving the PGA to the rail I need a VSS reference when measuring the crystal detector. The rest of the time I want the PGA referenced to AGND. No driver is provided to switch the PGA amplifier reference dynamically, but it can be set to VSS in the GUI. I am assuming it can be done dynamically. Is that true? Could someone give me a nickel tour on how to do this for a pga placed at ACB01.