A basic op-amp circuit has a zener and rectifier diode connected in the feedback path. Calculate the maximum positive voltage. Where, zener voltage = 5.1 v and voltage drop across the forward biased zener = 0.7v?
A. VO= 5.8v
B. VO= 9.9v
C. VO= 4.7v
D. VO= 7.1v
Answer:A
A basic op-amp circuit has a zener and rectifier diode connected in the feedback path. Calculate the maximum positive voltage. Where, zener voltage = 5.1 v and voltage drop across the forward biased zener = 0.7v?
A. VO= 5.8v B. VO= 9.9v C. VO= 4.7v D. VO= 7.1v
Explanation: Initially, rectifier diode will be reverse biased and makes the op-amp to operate in open loop configuration. So, the output voltage is obtained till the rectifier diode is forward bias and zener goes into avalanche condition. Hence, the maximum positive output voltage VOz +VD (VD –> voltage drop across rectifier diode).