Question

QUESTION 22 The circuit shown has RF - 50 112 and R; -8K2. The following values are obtained from the op-amp's data sheet: Aol - 70,000, Zin - SM2 and Zout - 75 22 Determine the closed-loop voltage gain Vio V. OV, Linn 0 -6.23 O 6.25 0 -7.25 O 7.25 O1

Answer 1

+ va Ri V2 Ven 3500x10" Vin Given R, = 8ke, R = 50kr Vin Aoi = TOOOO Zin=512, Zout = 752 where Vin= V, -12 Equivalent Circuit RE Vo - Zin Povin analysis, at rode - V2-v. V2-vo R Zin Rp Vo (: Ven=vo-ve) Va (1 2 + 1 p) - th 20 RE Vin Vo * Va= (1-379x102) Vin+ (0-1379) 5M 50k Egn At node Vo-V2 Vo-Aol Vo RF Zo + 1/3) - 1 2 - Aoi Vin RE Zo Vo (20 + RF) Bo (V2) - Ao RE Vino 1 - 70x10x 8x50k Vino Vo (75 +50k) - 15 ( 10379x103 Vin +0.137980) -- Vol 50.075K - 10.345) 8 xlo ven - 70x10x 50k Vino 6 Vo 50.065 k) = Apply nodal = 0 O Na SK + Box) - 8K Vin + 103.448

Vin 0.0143103 Vo Vin = V, - 12 we have → V - Vin & Val - Vin +(1.319x103 Ven+ 0.1379 Vo) 9.00 1379 Vin & 0.1379 Vo - 1.001379 (0.0143 x 103 ) +0.1379 Vo neglicible. Vi 0.1379 Vo 7.25 Vo closed loop gain 0.1379 V (option o