Explain voltage to frequency converter using op-amp

Explain voltage to frequency converter using op-amp  

Explain voltage to frequency converter using op-amp.

Solution:

A voltage to frequency converter produces a periodic signal whose frequency is proportional to an analog voltage. The periodic signal can be triangular or square V to F converter can be constructed using two operational amplifiers. One acts as an integrator while second one is a regenerative comparators. V to F converter can be constructed using two operational amplifiers. One acts as an second one is a regenerative comparators.

Working of the circuit can be explained as follows:

1. Let us assume that the output of comparator A., is in positive Saturation Vot.

2. Di is reverse biased and the output of integrator falls linearly. The rate of falling is decided by the input vallage Vin.

3 When the integrator output reaches a level - Vo" R₁/R₁ the comparator switches to negative output stage. 4. Diode D., becomes forward blased and the integrant output starts increasing

5. When the integratos amput reaches to -Vo RilR₂, the comparator switches back to positive saturation and the cycle repeats 

6. Thus at the output of opamp As, triangular output is obtained while comparator output is pulses.

7. The Frequency of oscillation is

Explain voltage to frequency converter using op-amp