| **.subckt tb_loop_filter |
| VSS vss GND {vss} |
| vdd vdd vss {vdd} |
| Vref A vss PULSE(0 1.0 0 1p 1p {Tref/2} {Tref}) DC {vin} AC 0 |
| x1 vss A vc loop_filter |
| x2 vss A vc_pex loop_filter_pex_c |
| **** begin user architecture code |
| |
| |
| |
| * Parameters |
| .param kp = 1.0 |
| .param vdd = kp*1.8 |
| .param vss = 0.0 |
| .param vin = vdd |
| .param fref = 5e6 |
| .param Tref = 1/fref |
| .param iref = 100u |
| .param vd0 = 0.0 |
| .param R1 = 1.6k |
| .param C1 = 33.5p |
| .param C2 = 6.7p |
| |
| .options TEMP = 50.0 |
| .options RSHUNT = 1e20 |
| |
| * Models |
| .lib ~/skywater/skywater-pdk/libraries/sky130_fd_pr_ngspice/latest/models/corners/sky130.lib TT |
| .include ~/caravel_analog_fulgor/xschem/simulations/loop_filter_pex_c.spice |
| |
| * Data to save |
| |
| |
| * Simulation |
| .control |
| |
| tran 0.01ns 200ns |
| meas tran t1 when v(vc)=0.63 |
| meas tran t2 when v(vc_pex)=0.63 |
| let R = t1/0.5p |
| let Rpex = t2/05.p |
| print R Rpex |
| plot v(vc) v(vc_pex) |
| .endc |
| |
| |
| **** end user architecture code |
| **.ends |
| |
| * expanding symbol: loop_filter.sym # of pins=3 |
| * sym_path: /home/dhernando/caravel_analog_fulgor/xschem/loop_filter.sym |
| * sch_path: /home/dhernando/caravel_analog_fulgor/xschem/loop_filter.sch |
| .subckt loop_filter vss in vc_pex |
| *.iopin in |
| *.iopin vss |
| *.iopin vc_pex |
| XC1 vc_pex vss sky130_fd_pr__cap_mim_m3_1 W=25 L=25 MF=25 m=25 |
| XC2 in vss sky130_fd_pr__cap_mim_m3_1 W=20 L=20 MF=9 m=9 |
| XR2 vc_pex net1 vss sky130_fd_pr__res_high_po_5p73 W=5.73 L=22.92 mult=1 m=1 |
| XR1 vc_pex net1 vss sky130_fd_pr__res_high_po_5p73 W=5.73 L=22.92 mult=1 m=1 |
| XR3 net1 in vss sky130_fd_pr__res_high_po_5p73 W=5.73 L=22.92 mult=1 m=1 |
| .ends |
| |
| .GLOBAL GND |
| ** flattened .save nodes |
| .end |
