The solution is given for this opAmp circuit. The circuit is capacitively couple
ID: 1927776 • Letter: T
Question
The solution is given for this opAmp circuit. The circuit is capacitively coupled. I just dont understand how the equation for Vout =VA+ (1M/1K) Vos. Here Vos is the offest voltage. Could u plz explain in steps how the vout was obtained. I would give it a life saver rating. plz help.
Solution:
lets consider voltage between 1K and ground =VA.
Vos=VA.
Vout=VA+Vos(1M/1K). This is solution. I dont get why vos is multiplied with (1M/1K) and why do we add VA.
sorry i just drew the circuit twice by mistake.
a
Explanation / Answer
the voltage at the -ve terminal will be same as positive which is Vos.
therefore
the Current in left 1M resistance will be zero.
and current in the 1k resistance will be VA/1k = Vos/1k (since Va = Vos)
from kirchoff's current law we can write that current at Va node will be zero therefore
(VA - Vout)/1M + Vos/1k = 0
=> Vout = VA + Vos(1M/1K)
If you have any further doubt then ask me.