.subckt avsd_opamp vdd vss in1 in2 out2 gnd 
* Stage 1 - Differential amplifier
xm1 net-_m1-pad1_ in1 net-_m1-pad3_ net-_m1-pad3_ sky130_fd_pr__nfet_01v8 l=1 w=1.79
xm2 out1 in2 net-_m1-pad3_ net-_m1-pad3_ sky130_fd_pr__nfet_01v8 l=1 w=1.79
xm3 net-_m1-pad1_ net-_m1-pad1_ vdd vdd sky130_fd_pr__pfet_01v8 l=1 w=10
xm4 out1 net-_m1-pad1_ vdd vdd sky130_fd_pr__pfet_01v8 l=1 w=10

* Current Mirror
xm5 net-_m1-pad3_ ref vss vss sky130_fd_pr__nfet_01v8 l=1 w=20
xm6 ref ref vss vss sky130_fd_pr__nfet_01v8 l=1 w=10

* Stage 2 - PMOS Common Source Amplifier
xm7 out2 out1 vdd vdd sky130_fd_pr__pfet_01v8 l=1 w=62.83
xm8 out2 ref vss vss sky130_fd_pr__nfet_01v8 l=1 w=62.83


.ends