Question

Determine the voltage input to the inverting terminal of an op amp when −40 μV is applied to the non-inverting terminal and the output through an open-loop gain of 150,000 is 15 V.

Answer 1

Answer:

The voltage input to the inverting terminal is 60μV

Explanation:

Given;

open-loop gain, A = 150,000

output voltage, V₀ = 15 V

voltage at the inverting input, $V_n$ = −40 μV = 40 x 10⁻⁶ V

The relationship between output voltage and voltage at the inverting input is given as;

$V_o = A(V_p -V_n)\\\\15 = 150,000(V_p -(-40*10^{-6}))\\\\15 = 150,000 (V_p +40*10^{-6}) \\\\V_p +40*10^{-6} = \frac{15}{150,000} \\\\V_p + 40*10^{-6} = 1 *10^{-4}\\\\V_p + 40*10^{-6} = 100 *10^{-6}\\\\V_p = 100 *10^{-6} - 40*10^{-6}\\\\V_p = 60 *10^{-6}\\\\V_p = 60 \ \mu V$

Therefore, the voltage input to the inverting terminal is 60μV