3.2.3. Common-Mode Rejection Ratio (CMRR)

Try these first

1. 1.

   What does CMRR stand for?

   Hint

   Consider what it means in relation to operational amplifiers.

2. 2.

   How is CMRR calculated?

   Hint

   Remember the definitions of open-loop gain and common-mode gain.

3. 3.

   What is the purpose of CMRR in an operational amplifier?

   • To increase output power
   • To filter out common signals
   • To amplify all inputs
   • To reduce output impedance

   Hint

   Think about what CMRR stands for.

4. 4.

   True or False: A high CMRR is desirable in operational amplifiers.

   Hint

   Consider its importance in audio applications.

5. 5.

   An op-amp has an open-loop differential gain of 400 and a common-mode gain of 10. Calculate the CMRR in both ratio and decibels.

   Hint

   Use both the ratio and the decibel formula.

6. 6.

   Describe a scenario where low CMRR could lead to failure in an application. Explain the impact.

   Hint

   Think about the function of the device and consequences of noise.