Question

Find the input voltage of an ideal op-amp. It’s one of the inputs and output voltages are 2v and 12v. (Gain=3)

Answer 1

Given:

Input Voltage 1 (Vin₁) = 2V

Output Voltage (Vout) = 12V

Gain A = 3

To find:

Input Voltage 2 (Vin₂)

Solution:

Formula used:

Vout = A(Vin₁ - Vin₂)

12 = 3(2 - Vin₂)

4 = 2 - Vin₂

Vin₂ = 2 - 4

Vin₂ = -2V

Therefore, input voltage of an ideal op-amp is -2V.

Ideal Op-Amp:

• Input currents are zero.
• Two Op-Amp inputs have the same voltage.