Other Parts Discussed in Thread: OPA187
As I understand it, PSRR+ is 20log(dVout/dVdd) with AC excitation on VDD only, with the op amp set up as a follower and the non-inverting input grounded (mid-rail). Likewise, PSRR- is with AC excitation on VSS. The test for both PSRR+ and PSRR- will cause common mode signal at 6dB down from the excitation amplitude. At 1kHz, PSRR- = 55dB and PSRR+=95dB, yet CMRR, at 140dB, is much more than 6dB above the noisier of the two. How can this be?
