Electronics and Communication Engineering - Analog Electronics - Discussion

Discussion Forum : Analog Electronics - Section 2 (Q.No. 48)
48.
A difference amplifier using op-amp has closed loop gain = 50. If input is 2 V to each of inverting and non-inverting terminals, output is 5 mA. Then CMRR =
20000
2000
200
20
Answer: Option
Explanation:

.

Discussion:
4 comments Page 1 of 1.

Shiva said:   6 years ago
Cmrr = gm*re.
gm = 50 is given so re=v/I.
Cmrr = 50 * 2/5m = 20000.

Rommel said:   8 years ago
CMRR = (Differential gain/ Common mode gain).

Common mode gain = Output/Input = 5mV/2V = 2.5x10-3,
Differential gain = 50,
CMRR = 50/2.5x10-3 = 20000.

Bismi said:   9 years ago
cmrr = (A * Vin/Iout).

Archana said:   10 years ago
What is the formula?

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