.
http://www.electronics-tutorials.ws/opamp/opamp_1.html
http://www.linear.com ( Linear Technology )
http://www.analog.com ( Analog Devices)
http://www.ti.com ( Texas Instruments )
Design with Operational Amplifiers and Analog Integrated Circuits , Sergio Franco, McGrawHill
.
Circuit symbol of op amp
Equivalent circuit for ideal op amp
Inverter amplifier configuration
.
CMMR
COMMON-MODE REJECTION RATIO
One important measure of the goodness of an op amp circuit is the CMRR.
Due to transistor nonidealities, some small amount of amplification occurs due to the common signal of both inputs.
The op amp common-mode rejection ratio (CMRR) is the ratio of the common-mode gain to differential-mode gain.
When the common-mode rejection ratio is expressed in dB, it is generally referred to as common-mode rejection (CMR).
Typical low frequency CMR values can be between 70 dB and 120 dB, but at higher frequencies, CMR deteriorates.
.
.
.
.
.
References
CMRR ( http://www.ece.cmu.edu/~ee321/spring99/LECT/lect8feb5.pdf )
Op Amp Common-Mode Rejection Ratio (CMRR) (analog Devices.com)
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Techs it easy 