|  | .lib "../sky130_fd_pr/models/sky130.lib.spice" tt | 
|  |  | 
|  | **.subckt 7bitdac_tb | 
|  | x1 x1_inp1 x1_inp2 x1_vdd 0 x1_d0 x1_d1 x1_out_v x1_d2 x1_d3 x1_d4 x1_d5 x1_d6 7bitdac | 
|  |  | 
|  | V1 x1_vdd 0 dc 3.3 | 
|  | V2 x1_d0 0 PULSE 0 1.8 0 1p 1p 5u 10u | 
|  | V3 x1_d1 0 PULSE 0 1.8 0 1p 1p 10u 20u | 
|  | V4 x1_inp2 0 dc 0 | 
|  | V5 x1_inp1 0 dc 3.3V | 
|  | V6 x1_d2 0 PULSE 0 1.8 0 1p 1p 20u 40u | 
|  | V7 x1_d3 0 PULSE 0 1.8 0 1p 1p 40u 80u | 
|  | V8 x1_d4 0 PULSE 0 1.8 0 1p 1p 80u 160u | 
|  | V9 x1_d5 0 PULSE 0 1.8 0 1p 1p 160u 320u | 
|  | V10 x1_d6 0 PULSE 0 1.8 0 1p 1p 320u 640u | 
|  | **.ends | 
|  | * expanding   symbol:  /home/harshitha/Desktop/xschem/xschem_library/7bitdac.sym # of pins=12 | 
|  |  | 
|  | .subckt 7bitdac inp1 inp2 vdd gnda d0 d1 out_v d2 d3 d4 d5 d6 | 
|  | *.ipin inp1 | 
|  | *.ipin inp2 | 
|  | *.iopin vdd | 
|  | *.iopin gnda | 
|  | *.ipin d0 | 
|  | *.ipin d1 | 
|  | *.opin out_v | 
|  | *.ipin d2 | 
|  | *.ipin d3 | 
|  | *.ipin d4 | 
|  | *.ipin d5 | 
|  | *.ipin d6 | 
|  | R1 x1_vref5 x2_vref1 250 | 
|  | x3 x1_out_v vdd out_v d6 gnda x2_out_v TG2 | 
|  | x1 inp1 x1_vref5 vdd gnda d0 d1 x1_out_v d2 d3 d4 d5 6bitdac | 
|  | x2 x2_vref1 inp2 vdd gnda d0 d1 x2_out_v d2 d3 d4 d5 6bitdac | 
|  | .ends | 
|  |  | 
|  | * expanding   symbol:  /home/harshitha/Desktop/xschem/xschem_library/6bitdac.sym # of pins=11 | 
|  |  | 
|  |  | 
|  | .subckt 6bitdac inp1 inp2 vdd gnda d0 d1 out_v d2 d3 d4 d5 | 
|  | *.ipin inp1 | 
|  | *.ipin inp2 | 
|  | *.iopin vdd | 
|  | *.iopin gnda | 
|  | *.ipin d0 | 
|  | *.ipin d1 | 
|  | *.opin out_v | 
|  | *.ipin d2 | 
|  | *.ipin d3 | 
|  | *.ipin d4 | 
|  | *.ipin d5 | 
|  | R1 x1_vref5 x2_vref1 250 | 
|  | x3 x1_out_v vdd out_v d5 gnda x2_out_v TG2 | 
|  | x1 inp1 x1_vref5 vdd gnda d0 d4 d1 x1_out_v d2 d3 5bitdac | 
|  | x2 x2_vref1 inp2 vdd gnda d0 d4 d1 x2_out_v d2 d3 5bitdac | 
|  | .ends | 
|  |  | 
|  | * expanding   symbol:  /home/harshitha/Desktop/xschem/xschem_library/5bitdac.sym # of pins=10 | 
|  |  | 
|  | .subckt 5bitdac inp1 inp2 vdd gnda d0 d4 d1 out_v d2 d3 | 
|  | *.ipin inp1 | 
|  | *.ipin inp2 | 
|  | *.iopin vdd | 
|  | *.iopin gnda | 
|  | *.ipin d0 | 
|  | *.ipin d4 | 
|  | *.ipin d1 | 
|  | *.opin out_v | 
|  | *.ipin d2 | 
|  | *.ipin d3 | 
|  | R1 x1_vref5 x2_vref1 250 | 
|  | x3 x1_out_v vdd out_v d4 gnda x2_out_v TG2 | 
|  | x1 inp1 x1_vref5 vdd gnda d0 d3 d1 x1_out_v d2 4bitdac | 
|  | x2 x2_vref1 inp2 vdd gnda d0 d3 d1 x2_out_v d2 4bitdac | 
|  | .ends | 
|  |  | 
|  |  | 
|  | .subckt 4bitdac inp1 inp2 vdd gnda d0 d3 d1 out_v d2 | 
|  | *.ipin inp1 | 
|  | *.ipin inp2 | 
|  | *.iopin vdd | 
|  | *.iopin gnda | 
|  | *.ipin d0 | 
|  | *.ipin d3 | 
|  | *.ipin d1 | 
|  | *.opin out_v | 
|  | *.ipin d2 | 
|  | R1 x2_vref1 x1_vref5 250 | 
|  | x3 x1_out_v vdd out_v d3 gnda x2_out_v TG2 | 
|  | x1 inp1 x1_vref5 vdd gnda d0 d2 d1 x1_out_v 3bitdac | 
|  | x2 x2_vref1 inp2 vdd  gnda d0 d2 d1 x2_out_v 3bitdac | 
|  | .ends | 
|  |  | 
|  | * expanding   symbol:  /home/harshitha/Desktop/xschem/xschem_library/3bitdac.sym # of pins=8 | 
|  |  | 
|  |  | 
|  | .subckt 3bitdac inp1 inp2 vdd gnda d0 d2 d1 out_v | 
|  | *.ipin inp1 | 
|  | *.ipin inp2 | 
|  | *.iopin vdd | 
|  | *.iopin gnda | 
|  | *.ipin d0 | 
|  | *.ipin d2 | 
|  | *.ipin d1 | 
|  | *.opin out_v | 
|  | R1 x1_vref5 x2_vref1 250 | 
|  | x1 vdd inp1 gnda x1_out_v d1 d0 x1_vref5 2bitdac | 
|  | x2 vdd x2_vref1 gnda x2_out_v d1 d0 inp2 2bitdac | 
|  | x3 x1_out_v vdd out_v d2 gnda x2_out_v TG2 | 
|  | .ends | 
|  |  | 
|  | * expanding   symbol:  /home/harshitha/Desktop/xschem/xschem_library/2bitdac.sym # of pins=7 | 
|  |  | 
|  | .subckt 2bitdac  vdd vref1 gnda out_v d1 d0 vref5 | 
|  | *.ipin vref1 | 
|  | *.ipin vref5 | 
|  | *.ipin d0 | 
|  | *.ipin d1 | 
|  | *.iopin vdd | 
|  | *.iopin gnda | 
|  | *.opin out_v | 
|  | x1 x1_inp1 vdd x1_vout d0 gnda x1_inp2 TG2 | 
|  | x2 x2_inp1 vdd x2_vout d0 gnda vref5 TG2 | 
|  | x3 x1_vout vdd out_v d1 gnda x2_vout TG2 | 
|  | R1 x1_inp1 vref1 500 | 
|  | R2 x1_inp2 x1_inp1 500 | 
|  | R3 x2_inp1 x1_inp2 500 | 
|  | R4 vref5 x2_inp1 250 | 
|  | .ends | 
|  |  | 
|  |  | 
|  | * expanding   symbol:  /home/harshitha/Desktop/xschem/xschem_library/TG2.sym # of pins=6 | 
|  |  | 
|  | .subckt TG2  inp1 vdd vout din 0 inp2 | 
|  | *.ipin inp1 | 
|  | *.ipin inp2 | 
|  | *.opin vout | 
|  | *.ipin din | 
|  | *.iopin vdd | 
|  | *.iopin gnda | 
|  |  | 
|  | XM1 dinb din 0 0 sky130_fd_pr__nfet_01v8 L=0.15 W=0.6 | 
|  | XM2 dinb din vdd vdd sky130_fd_pr__pfet_01v8 L=0.15 W=1.2 | 
|  |  | 
|  | XM7 dd dinb 0 0 sky130_fd_pr__nfet_01v8 L=0.15 W=0.6 | 
|  | XM8 dd dinb vdd vdd sky130_fd_pr__pfet_01v8 L=0.15 W=1.2 | 
|  |  | 
|  | XM3 vout dinb inp2 inp2 sky130_fd_pr__nfet_01v8 L=0.15 W=0.6 | 
|  | XM4 inp1 dd vout vout sky130_fd_pr__nfet_01v8 L=0.15 W=0.6 | 
|  |  | 
|  | XM5 vout dinb inp1 inp1 sky130_fd_pr__pfet_01v8 L=0.15 W=1.2 | 
|  | XM6 inp2 dd vout vout sky130_fd_pr__pfet_01v8 L=0.15 W=1.2 | 
|  |  | 
|  | .ends | 
|  |  | 
|  | .tran 2u 640u | 
|  | .control | 
|  | run | 
|  | plot x1_d0 x1_d1 x1_d2 x1_d3 x1_d4 x1_d5 x1_d6 x1_out_v | 
|  |  | 
|  | .endc | 
|  | .end |