3.2. Basic Principles of CMOS Operational Amplifiers

Try these first

1. 1.

   What is the function of a differential pair in an op-amp?

   Hint

   Think about what it means to amplify the difference.

2. 2.

   Define open-loop gain.

   Hint

   Consider the amplification that happens in an op-amp without any feedback mechanism.

3. 3.

   What is the primary function of a differential pair in an op-amp?

   • To amplify input voltage
   • To filter signals
   • To amplify the voltage difference

   Hint

   Think about what it means to amplify the difference.

4. 4.

   True or False: High CMRR is important for an operational amplifier.

   • True
   • False

   Hint

   Consider what happens when common signals are amplified along with the desired signal.

5. 5.

   Design a basic CMOS op-amp using NMOS and PMOS transistors while defining the values for open-loop gain and input/output impedance that would meet typical application requirements.

   Hint

   Think about how transistor configurations will affect your gain and impedance.

6. 6.

   Given the open-loop gain of an op-amp of 1500 and a common-mode gain of 50, calculate the CMRR and discuss the implications on the amplifier's noise rejection.

   Hint

   Use the CMRR formula as a guide.