instrumentation amplifier

http://en.wikipedia.org/wiki/Instrumentation_amplifier

CMRR-common mode rejection ratio = ^ VIcm/^ VOcm*Av 100-120db
op-am ablity to supress common-mode input voltage(same amplitude, waveform, freuency, shape) simultaneously at both input. Ideally. v1-v2=0, vo=0.

PSRR-power supply rejection ratio= ^ VIapsl/^ VOapsl*Av 80-100db
asychronous  input voltage(same amplitude, waveform, freuency, shape)