How to deisgn sizes of differential amp in spectre

[Safiya]

HI,
How to design sizes and which steps are necessary in a systematic way for single stage 5 tier amp , and then 2nd stage.
regards,
Safiya

 

[kenambo]

Hi,

To desiogn an op-Amp you must design proper biasing ciruits which is essential for the proper operation...

For current mirror you have to find appropriate length which makes good mirroring of current... And it depends on which technology you are using....

Then choose somewhat bigger area for the differential input pair of the Op-Amp , this bigger are is for reducing unneccesary offset problems...

Then for the gain stage use cascode stage ... which contains Pmos and N mos devices...
You can find many good opamp designs and sizes for the op-amp in websites .. try them...

thanks,,,