Other Parts Discussed in Thread: OPA197, OPA333, OPA2387, OPA2191, OPA2197, OPA2192
the following curcuit is a constane current circuit. and the output current range is 200nA to 4uA. we found that the circuit will not output when use OPA188 on U31. and the circuit works OK with OPA197 or OPA333 on U31.
I think OPA188 should be OK for this circuit. Could anybody help point out the root cause of the problem?