This preview shows page 1. Sign up to view the full content.
Sample problems Topic: Operational Amplifiers Statement of problem The opamps in the circuit are ideal. - + - + a i 5 V − 5 V − 5 V 5 V 400 mV 30 k Ω 120 k Ω 1 k Ω 90 k Ω 15 k Ω 500 mV (a) Find a i . (b) Find the value of the right source voltage for which 0 a i = . Solution (a) The idea is to find out output voltages of the two opamps, and then to find out the current in between. The left opamp is virtually grounded, so the current flowing through the left source is 1 500 33.3 15 mV iA k μ − == − Ω Then its output voltage is obtained using KVL 11 90 3 o vikV =−× Ω= (1) Repeating the same process for the right source and opamp, its output voltage is obtained
This is the end of the preview. Sign up to access the rest of the document.