5.4. Difference Amplifier

Try these first

1. 1.

   What is the primary function of a Difference Amplifier?

   Hint

   Think about what the name suggests.

2. 2.

   Define Common-Mode Rejection Ratio (CMRR).

   Hint

   What does CMRR specifically measure?

3. 3.

   What does a Difference Amplifier primarily output?

   • The sum of two voltages
   • The difference between two voltages
   • The average of two voltages

   Hint

   Consider what 'difference' means.

4. 4.

   True or False: A Difference Amplifier has no effect on common-mode signals.

   • True
   • False

   Hint

   Think about its function.

5. 5.

   Design and calculate the output of a Difference Amplifier circuit if V1 = 3V, V2 = 1V, R1 = R2 = 10kΩ, and R3 = R4 = 20kΩ. What would be the output voltage?

   Hint

   Use the formula for the output of a Difference Amplifier.

6. 6.

   Given a Difference Amplifier with a CMRR of 80 dB and a common-mode gain of 0.01, calculate the differential voltage gain.

   Hint

   Recall that CMRR indicates how much more the differential gain is than the common-mode gain.