Hi everyone, I designed an OTA Miller with the SKY130 PDK. And obtained GBW=32MHz and a DC gain of 48,5dB. I didn't work a lot on the design so I think I can improve those parameters. But my question is how much ? What is the maximum GBW and DC gain I can achieve with the SKY130 PDK ?

The maximum frequency of a technology is based on its minimum transistor length. You could design an OTA with no load, and it would have its transistor and routing parasitics. So, 32 MHz GBW is not a good performance metric if there is no power consumption and load. I've designed a 40 dB gain 100 MHz OTA with a 10 pF load and about 10 mA current consumption for 60 degree phase margin. It means nothing. I could use a 1 pF load, I could decrease phase margin, use shorter transistors, decrease CMRR and PSRR, and improve GBW. I can increase transistor length and increase gain. I could use four gain stages and have an incredibly complex stabilization circuit and have voltage gains above 120 dB. The important thing here is not how much you can increase a number, it is how much your application needs, and how efficiently you can reach the specs after layout extraction and PVT. And, mostly important, if you can deliver your design in time for your deadlines.

Okay, I understand. Thanks for your answer !