Hi Charles,
I know what is going on. You are applying the OPA4188 amplifier section as a comparator, with a 2.21 V reference voltage applied to the inverting input. When you drive the non-inverting input to the 1.45 V level you forward bias one of the…
David,
We have several quad op amps with the input common-mode voltage range beyond both rails; please see take a look at OPA4191, OPA4192, OPA4196 and OPA4197.
