Question

2- To make an inverting amplifier with a high input resistance associated with a large amplification, we use the following circuit (Figure 2) where the OA is supposed to be ideal. Examine the different performance characteristics by answering to the following questions: = Vio R1 - Figure 2 : Inverting amplifier circuit - a- Give the expression of the gain b- We give R3 = 1000R4 and R4 = R2, what must be the relation between R1 and R2 to have the same amplification with an inverter circuit? C- Prove that when we make a simple switch between Vi and the Ground, the new gain will be: w A; = (R1 + R2)(R3 + R4) + R3R4 R1R4

Please solve a,b & c , with clear handwriting & explaining the steps in a simple way.

Answer 1

Y BRA Let the voltage at Non Investing terminal va The voltage at both Inverting & Non- Inverting terminals are equal : Vozo, Vaavo. Varo. The Xoltage acrog R& Vx=24 Vo. (By v. Divisi Rg+RA Apply Ict at va vo-va Va-Vx to a R b 4 enters into op-an zero. v لياى RI to che ) vo - (+24)R20 - (Rg+R4) R2 RIRA.

Given Rg = 1000Ry, Ry =R2. is input In order to have same Amplification is ro then output should be ve eqn o voo = a (Rg TR4) R2 RIRA. 1 = - (1000Ry+R4) R2 R,R4 1 = - 100124 Re O RIBG le = - 100122