[SOLVED] How to convert double ended output to single ended output in Fully differential opamp

[Munaaf.M.A]

I need to convert double end of Fully differential opamp to single ended as i need only one output pin in order to design a filter. I have used VCVS but that is not a correct procedure as we dont get layout of VCVS. so i need suggestions for the above question. Thanking You. Waiting for a quick response. in CADENCE virtuoso environment

 

[FvM]

There's nothing against using the output of a fully differential OP only single ended. What's your exact problem?

 

[amaximus]

I am going to echo what FvM said above. You can just grab one of the outputs of the differential opamp and tie it to your next stage. You will lose half of the effective differential gain that way.

On the other hand, you can modify the differential opamp to have current mirror load to simply convert it to a single-ended output. You would retain the full gain that way.

 

[crutschow]

Here's the current-mirror differential to single-ended circuit that amasimus mentioned.
The current-mirror has the advantage of higher gain and it maintains the common-mode rejection of the differential amp, which pulling the signal from one transistor does not.

 

[Osman Ceylan]

Use a Balanced-to-unbalanced conveter. shortly BalUn. 1:1 transformer is also very OK.

 

[Eslam Saad]

with current mirror technique
feed the current of one o/p to another by mirroring it