Design of Two Stage CMOS Op Amp

My experience throughout the marathon was really fascinating and
A brief of what I went through is as follows

The start of marathon said that we had to select a circuit (literature survey) and do a simulation on the same which seemed quite simple.
The selection of circuit was a bit hard, but still I came out with this circuit sooner and started my way ahead for simulation, wereby

I designed the circuit with reference circuit which was implemented using 0.5um technology.
I didn't get the output waveforms correct until I surfed more and found a correct aspect ratio of MOSFETs being used.

I refered a YouTube video for the same.

With the help of my friend I was able to locate the correct circuit and implemented it using eSim

I tried first using other SPICE software(LTSpice)(in which I'm comfortable with) for checking the correctness of the circuit

I installed different version of ngspice which actually executed the netlists faster.

My college Lab simulations helped in understanding the netlist, hence I could easily modify netlist for trail checks

I tried simulating the circuit in LTSpice once I got the output, I copy pasted the netlist and with few modifications I could run it on ngspice
The net naming methodology of both LTSpice and that of eSim's KiCad were different thought the netlist ran successfully in both LTSpice and ngspice

I created a KiCad schematic with LTSpices' and then modified the netlist generated by eSim so as to use the sky130 pdk

The net order of the current source was different in both LTSpice and eSim, I was able to figure that out after nearly 10 trails
The circuit was then successfully executed, both transient and frequency response was obtained

The circuit provided a good gain of nearly 100 V/V (or 40 dB) with a Unity gain bandwith of about 4.5MHz


The netlist includes both the transient and frequency analysis 
and the transient analysis is commented out.
Running .cir.out brings about frequency response
and.. for transient analysis
Please comment the AC analysis part and uncomment the transient part

(Please include the sky130 model files in the current working directory)
(the lib is included as .lib "sky130_fd_pr/models/sky130.lib.spice" tt )

It was because of internet and my friend's help I could actually simulate a Two Stage CMOS Op Amp with sky130 nm technology

All this was made possible by Team FOSSEE by organising such a Circuit Simulation Marathon
Thanks for such an initiative!!!


Thank you!!