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I am quite new to amplifier.

I want to design a common source amplifier. And here is my design in spice: enter image description here

Since the supply voltage is 6V.

So i want my amplifier's operating point at 3V. So before i add the active loading.It is quite easy to do that: enter image description here

Just want to know after my amplifier is actively loaded, how should i adjust the operating point? Adjust the V1?

Mirage
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    Your P- MOS is wrongly connected. Source terminal to Vdd. Also try to read this http://www.ittc.ku.edu/~jstiles/412/handouts/6.5%20The%20Common%20Source%20Amp%20with%20Active%20loads/section%206_5%20The%20Common%20Source%20Amp%20with%20Active%20Loads%20lecture.pdf – G36 Jan 30 '22 at 20:22
  • What you are trying to achieve? This type of circuit is never built alone as a single stage. But it can be used as a part of a larger circuit. Thus, to make it work you need some kind of negative feedback loop to set the DC bias point. – G36 Feb 01 '22 at 16:38
  • Hey @G36, just have a little question about operating point. Is it the voltage between drain and source of M3? And also, in my circuit, the calculated gain is quite high due to the high output resistance of M6 and M3, but the output shows that the gain is around 3. How to calculate that, i know its bias conditon that limits the final gain, but is there a way to calculate that? Thank you in advance!!!! – Mirage Feb 01 '22 at 20:05
  • Are you sure you want M3's body connected to source? You're generally supposed to use `nmos4` and `pmos4` symbols when doing IC design. That way you can connect all NMOS bodies to Vss and all PMOS bodies to Vdd. – Ste Kulov Feb 02 '22 at 10:05

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