| * Capacitor (4 terminal w/separate shield) value test |
| |
| * Include SkyWater sky130 device models |
| .include "../../../models/r+c/res_typical__cap_typical__lin.spice" |
| .include "../../../models/r+c/res_typical__cap_typical.spice" |
| .include "../../../models/capacitors/sky130_fd_pr__model__cap_vpp.model.spice" |
| |
| .param freq = 1Meg |
| .csparam freq = {freq} |
| |
| * Resistor bridge with capacitance |
| V1 N2 0 1.8 |
| IAC N3 N4 dc 0 ac 1 |
| |
| X1 N3 N4 0 0 sky130_fd_pr__cap_vpp_03p9x03p9_m1m2_shieldl1_floatm3 |
| * C34 N3 N4 50E-15 |
| |
| R1 N3 0 1.1Meg |
| R2 N4 0 1.2Meg |
| R3 N2 N3 1.3Meg |
| R4 N2 N4 1.4Meg |
| |
| .ac lin 1 {freq} {freq} |
| .control |
| run |
| echo capacitance |
| print imag(1/v(N4,N3))/2/PI/freq |
| quit |
| .endc |
| |
| .end |
