| *--------------------------------------------------------------------------- | 
 | * SPDX-FileCopyrightText: 2020 Efabless Corporation | 
 | * Licensed under the Apache License, Version 2.0 (the "License"); | 
 | * you may not use this file except in compliance with the License. | 
 | * You may obtain a copy of the License at | 
 | * | 
 | *     https://www.apache.org/licenses/LICENSE-2.0 | 
 | * | 
 | * Unless required by applicable law or agreed to in writing, software | 
 | * distributed under the License is distributed on an "AS IS" BASIS, | 
 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | 
 | * See the License for the specific language governing permissions and | 
 | * limitations under the License. | 
 | * | 
 | * SPDX-License-Identifier: Apache-2.0 | 
 | *--------------------------------------------------------------------------- | 
 | * Threshold test for POR circuit | 
 | * Determine gate voltage at which the HV NFET draws 240nA nominal | 
 | * | 
 | * Result:  0.7575V | 
 | *------------------------------------------------------------------- | 
 |  | 
 | .lib /usr/share/pdk/sky130A/libs.tech/ngspice/sky130.lib.spice tt | 
 |  | 
 | *---------------------------- | 
 | * Testbench circuit | 
 | *---------------------------- | 
 | Rtest vdda mir1 1MEG | 
 | Xm1 mir1 vin vss vss sky130_fd_pr__nfet_g5v0d10v5 w=2 l=0.8 | 
 |  | 
 | Vgate vin vss DC=0 | 
 | Vpwr vdda vss DC=3.3 | 
 | Rgnd vss 0 0.1 | 
 |  | 
 | *---------------------------- | 
 | * Testbench control | 
 | *---------------------------- | 
 | .control | 
 | * DC sweep from 0.7 to 0.8V | 
 | dc Vgate 0.7 0.8 0.001 | 
 | wrdata test.data Vpwr#branch vin | 
 |  | 
 | .endc | 
 |  | 
 | .end | 
 |  |