Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

why Vin+ is not equal to Vin- for opamp in closed loop

Status
Not open for further replies.

shineqi

Member level 1
Joined
Jan 16, 2007
Messages
36
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,286
Activity points
1,508
Hi friends:

what may cause the probelm about Vin+ is not equal to Vin- for a fully differential ota in a closed loop application?

Thanks
 

shineqi said:
Hi friends:

what may cause the probelm about Vin+ is not equal to Vin- for a fully differential ota in a closed loop application?
Thanks

Why do you expect both being equal ?
The difference between both inputs is never zero - however, for high gain opamps it approaches zero !
But for an OTA you have a situation which is completely different since the transconductance has a finite value which is rather low. Thus, the input differential voltage has a finite value.
 

you can calculate the input voltage difference if you know the DC gain of your amplifier
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top