Hello all,
It has been a while that Im searching about the DC voltage offset on an op amp out put and its effects on AC voltage which we care about. I have noticed in some designs that DC offset varies from 35 to few mili Volts on the op amp output. So what would be the effect on AC voltage (if it has any at all)? What are the limits?
I appreciate your consideration,
Cheers,
Alan.
It has been a while that Im searching about the DC voltage offset on an op amp out put and its effects on AC voltage which we care about. I have noticed in some designs that DC offset varies from 35 to few mili Volts on the op amp output. So what would be the effect on AC voltage (if it has any at all)? What are the limits?
I appreciate your consideration,
Cheers,
Alan.
The limits are the PSU rails (or the output stage swing if its not a R-R out opamp). The reason for keeping an opamp's DC output close to GND is because that's where the maximum signal handling is with the normal, symmetrical rails. Also it makes design of the subsequent stage simpler when not capacitively coupled. Otherwise, don't worry about the DC offset (unless feeding a trafo or transducer of some kind).
Thanks @abraxalito , it was really helpful , so if a design is ok as you said, no effect on AC signals then. Quality wise I mean?