The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl Design >> Analog Design >> Fully differential (differential in - differential out) OpAmp offset simulatoin https://designers-guide.org/forum/YaBB.pl?num=1554231923 Message started by 7IC7 on Apr 2nd, 2019, 12:05pm |
Title: Fully differential (differential in - differential out) OpAmp offset simulatoin Post by 7IC7 on Apr 2nd, 2019, 12:05pm Hello everyone, I have a question about the offset simulation of the fully differential amplifiers (differential in - differential out). I am not able to find a good resource that provides an understandable test bench (for offset simulations). The only link that I found is this one which is not complete: https://designers-guide.org/forum/Attachments/offsetFullyDiffopampV1.pdf Have you done this type of simulation before? If yes, please help. Regards, |
Title: Re: Fully differential (differential in - differential out) OpAmp offset simulatoin Post by Ken Kundert on Apr 2nd, 2019, 5:36pm Generally you just provide some feedback and then measure the difference in voltage between the two inputs. Placing the amplifier in a unity gain configuration works well. You might want to take a look at https://designers-guide.org/analysis/diff.pdf for general information on how to test differential circuits. -Ken |
Title: Re: Fully differential (differential in - differential out) OpAmp offset simulatoin Post by Salim2019 on Apr 7th, 2019, 2:14pm Hi, Connect your amplifier as a unity gain buffer, sweep differentially your inputs and record the output. I will assume you are working with single supply operation let say 3.3 V. So use two DC sources with 1.65 at each input with a variable callled X, now sweep X from -1.65 to 1.65, Now you have two output signals, ideally they must intersect at the point of X=0. any shift from this point is your offset voltage. Note I am talking about the x-axsis. Hope I could answered your question |
Title: Re: Fully differential (differential in - differential out) OpAmp offset simulatoin Post by kabir_fakir on May 3rd, 2019, 2:09pm Salim2019 wrote on Apr 7th, 2019, 2:14pm:
Yes SALIM is right. I have done same procedure with fully differential OTA. By the way, I have followed the doc cited by Ken Kudert. Good luck! |
The Designer's Guide Community Forum » Powered by YaBB 2.2.2! YaBB © 2000-2008. All Rights Reserved. |