Question

Problem 1: Implement a summing operational amplifier that its output voltage is 1 dvin2 - Vin3 v. = -3 - 5V in1 - 10-8e VT 100 dt The input resistance for Vint of the circuit should be 10 kl.

Answer 1

problemi Vin Vo = -3- 5 Vini 1 dvina dt -8 10 e VT 100 To implement above Summer we need knowledge of in verting and exponential amplifier, differe- operator. ntiator Inverting Amplifier Ri vi No + Vo -Rf Ri Vor-RF vi Ri Differentiator Rp Vi Vo dvi Rfc dt

Exponential Amplifier vi Rf Is Is = Reverse saturation current of Diode Vi Vo = - Rf Is e UT where ut = Thermal voltage =KT where = 8.6x103 evlk Ta temperature in Kelvin k= Boltzman constant

Rf= = 50k R=50k 3 V w Vini loka V. Vinz C vina 조 Is Vo = (RF) 3 v RF Vin3 R Vini ! dvinz Rfc dt - Rf Is e Vi lok given that Vo= -3 -5 Vini - dvinz dt Vinz VT -10 100 By comparing Rf R IR f =R RF 5 Rf=50k lok R= Rf = 150K

Rc=100 RE f => 50x103 C=100 C = Too 50x103 C = 0.002 500 = am Rf Is = 108 => 50 x103 Is = ها - Is= i -12 lo 5x104 Is = 0.2x1012 -13 Is = 2x10 A have Diode should current reverse saturation of 2X 10 i 3 A