*Three stage operational amplifier *** *** OPAMP SUBCIRCUIT *** *** .SUBCKT PFC.SUB VP VN VOUT IBIAS VB1 AVDD AVSS M00 IBIAS IBIAS AVDD AVDD PMOS W=#WM00_10# L=#LM1# * differential pair M10 1 IBIAS AVDD AVDD PMOS W=#WM00_10# L=#LM1# M=6 M11 2 VN 1 1 PMOS W=#WM11_12# L=#LM2# M12 3 VP 1 1 PMOS W=#WM11_12# L=#LM2# * folded cascode M13 4 IBIAS AVDD AVDD PMOS W=#WM13_16# L=#LM1# M=3 M16 5 IBIAS AVDD AVDD PMOS W=#WM13_16# L=#LM1# M=3 M14 4 VB1 2 AVSS NMOS W=#WM14_17# L=#LM3# M17 5 VB1 3 AVSS NMOS W=#WM14_17# L=#LM3# M15 2 4 AVSS AVSS NMOS W=#WM15_18# L=#LM4# M18 3 4 AVSS AVSS NMOS W=#WM15_18# L=#LM4# * second stage M20 6 5 AVDD AVDD PMOS W=#WM20# L=#LM6# M22 7 IBIAS AVDD AVDD PMOS W=#WM22# L=#LM1# M21 6 6 AVSS AVSS NMOS W=#WM21_23# L=#LM5# M23 7 6 AVSS AVSS NMOS W=#WM21_23# L=#LM5# * third stage M30 VOUT 5 AVDD AVDD PMOS W=#WM30# L=#LM6# M=22 M31 VOUT 7 AVSS AVSS NMOS W=#WM31# L=#LM7# M=5 * compensation CM1 5 VOUT #CC1# CM2 5 7 #CC2# .ENDS PFC.SUB *** *** SUPPLY VOLTAGES *** *** VDD VDD 0 #VSUPPLY# VSS VSS 0 0 *** *** BIAS VOLTAGE *** *** VVB1 VB1 VSS DC #VBIAS# *** *** BIAS CURRENT *** *** IIBIAS IBIAS VSS #IBIAS# *** *** SUB-CIRCUIT *** *** XOPAMP VP VN VOUT IBIAS VB1 VDD VSS PFC.SUB *** *** LOAD *** *** RL VOUT VX #RLOAD# CL VOUT VX #CLOAD# VX VX VSS '#VSUPPLY#/2' *** *** AC LOOP *** *** VIN VP VSS '#VSUPPLY#/2' AC 1 RX VN VOUT 1m AC=1E12 CX VN VSS 10 *** *** ANALYSIS *** *** .AC DEC 100 0.001 1E9 .PZ V(VOUT) VIN .PROBE AC VDB(VOUT) .PROBE AC VP(VOUT) .OP .OPTION POST UNWRAP .INCLUDE p.typ .INCLUDE n.typ .END