Instrumentation amplifiers are used to process and transport signals, and demand a very high CMRR. Figure 4. Basic differential amplifier. Figure 5. Instrumentation amplifier. To further appreciate ...

2. Discrete difference amplifier. Designed to amplify differential voltages, the operational amplifier itself provides good CMRR, but this is overwhelmed by the circuit surrounding it.

CMRR is therefore not degraded and an ordinary variable resistor can be used (close tolerance resistors must still be used for R1-R9, as for any differential amplifier). Assuming always that R1 = R5 ...

All of the differential-amp resistors are usually the same value, giving this stage a gain of 1. ... The common-mode rejection ratio (CMRR) reveals how well common-mode signals are cancelled.

The ability to strip the huge 7.5V DC signal that is common to both inputs is known as the Common Mode Rejection Ratio and is an important aspect when picking an instrumentation amplifier.

Analog Devices has released a set of differential-in differential-out amplifiers win a minimum CMRR (common-mode rejection ratio) of 94dB. Based on the existing LTC6363 differential amplifier which ...

In practice, a CMRR of at least 80 dB (10,000:1) is considered quite good. An amplifier such as the LeCroy DA1855A, for example, has a CMRR that exceeds the 80 dB level at low frequencies up to a few ...