Question

The circuit below is "Differential amplifier" The waveform of the input signal is shown below. The input signal is

(1) An expression of the gain of a closed loop on a circuit $R_{1},R_{2},R_{_{f}},R_{g}$
Use to induce. (formerly op-amp)
The analysis method can be used. KVL and KCL can be utilized properly.)

(2)When $R_{1}=R_{2},R_{_{f}}=R_{g}$ set the resistance value so that the closed loop gain is 2.5 and the output synchronized with the input signal.
Sketch the force signal (exactly mark the maximum and minimum values and cycles of the output signal on the output signal waveform).

Answer 1

Ri ए Uza Rg The above circuit is a difference Amplifier which means output voltage is directly propastional to difference of input voltage Here input voltage V, is applied to inverting terminal of op-Amp Iz is applied to non investing terminal of op-Amp In order to calculate total output voltage we have calculate the output voltage due vi alone and output V alone calculating the output voltage due to alone at the same time ų is set to tero due to When we are Y CS Scanned with CamScanner

Now the circuit is £ Ri > 쿄 Rg a ارا Applying KCL at ne rode FIB + If For an ideal op-Amp 18 = 15 co I1 = If u-va = va-vo R RE where Va is the voltage at investing terminal at node a ground concept Va because voltage at non inuesting terminal node bis ol using virtual CO Thren Va-4c0 V b co So Va co CS Scanned with CamScanner

due to y V- Ri o-vo, RE Voi = -RE RI Y Now we have to calculate output voltage due to non Investing terminal at the same time in terminal voltage is equal to zero le 4 20 Now the circuit is RE RI * Ra Rg Voz Voz = (1+ Rew Yo (1 + Reff Rg Total output voltage Vo = Votvor = (1+ Intege CS Scanned with CamScanner

of Ri Rz Vo=11HRE RI then vo=114 REV + (14RE Ritky). 112 etky) - Rey 4 Rp = Rz, Rf = Rg "-len Vo = lethel Petre) k een -V gain = (1+ R) ( ter) va Ri Jo VE ㄷ RI = Vo ku Hot 20 & ERg if R=R2 vo RI gain=2.5 then BE =25 RI Pf=2.581 Ashime Ri=1kr then f = 2.5k. then R=R2 = 1Kr , Rf = Rg = 2.5km CS Scanned with CamScanner