SKY130 gm/ID Explorer
An interactive, browser-based gm/ID characterisation tool for the SkyWater SKY130 open-source 130nm CMOS PDK.
Website
Open the tool in your browser. Click the link, or copy the URL:
Open the SKY130A gm/ID Explorer
https://nithinpuru.github.io/gmid/sky130a/
All PDKs (SKY130A, GF180MCU-D, IHP SG13G2):
Open the gm/ID Explorer (all PDKs)
https://nithinpuru.github.io/gmid/
Note: The PDK Reference panel is a summary and may contain inaccuracies. Always check values against the official SkyWater PDK documentation before relying on them.
What is this?
This tool lets you explore the gm/ID characteristics of 7 MOSFET variants in the SKY130 PDK directly in your browser. You don't need Python, MATLAB or a local install.
Derived from simulation data in chennakeshavadasa/gmid_SKY130, converted into a fully interactive Plotly dashboard with a comprehensive PDK reference panel pulled from the official skywater-pdk documentation.
Features
PDK Reference Panel
- Full explanation of all 7 MOSFET variants: LVT / SVT / HVT flavours and HV (5V/10.5V) devices
- Explanation of what LVT, SVT, HVT actually mean in SKY130 (same gate oxide, different Vt-adjust implants)
- Why
nfet_01v8_hvt does NOT exist in SKY130 (only PMOS HVT)
- HV device explanation — why
g5v0d10v5 is an extended-drain DMOS, not just a thick-oxide FET
- EP electrical specs: Vth₀, SubVt slope, Ioff, Vds limits for all devices
- 7-corner guide: TT / SS / FF / SF / FS / leak / wafer
- Instance parameter limits (Wmin, Lmin) — PMOS Lmin=0.35µm vs NMOS 0.15µm
- Designer's quick-reference cheatsheet
gm/ID Explorer
- 7 device variants: NMOS/PMOS SVT/LVT/HVT + HV family
- 7 interactive Plotly plots:
- gm/ID vs Vgs
- gm/ID vs Vov (= Vgs − Vth)
- gm/gds vs gm/ID (intrinsic gain)
- ID/W vs gm/ID (normalised current density)
- fT vs gm/ID (transit frequency)
- Cgd/Cgg vs gm/ID
- Cgs/Cgg vs gm/ID
- Overview mode — 6 plots simultaneously
- Channel length filter — per-L toggle or quick All/Short/Long
- Log scale toggles for X and Y
- PNG export of any plot
Device Summary
| Dataset name | PDK model | Type | Vdd | Lmin | Vth₀ typ | Notes |
|---|
| NMOS_01v8_SVT | nfet_01v8 | NMOS SVT | 1.8V | 0.15µm | ~0.49V | Standard workhorse |
| NMOS_01v8_LVT | nfet_01v8_lvt | NMOS LVT | 1.8V | 0.15µm | ~0.40–0.45V | Low-Vt, higher speed |
| PMOS_01v8_SVT | pfet_01v8 | PMOS SVT | 1.8V | 0.35µm | ~0.60–0.65V | Standard PMOS |
| PMOS_01v8_LVT | pfet_01v8_lvt | PMOS LVT | 1.8V | 0.35µm | ~0.52V | Low-Vt PMOS |
| PMOS_01v8_HVT | pfet_01v8_hvt | PMOS HVT | 1.8V | 0.35µm | ~0.74V | Low-leakage, power gating |
| NMOS_g5v0d10v5 | nfet_g5v0d10v5 | NMOS HV | 5V/10.5V | 0.5µm | ~0.78–0.85V | Extended drain DMOS |
| PMOS_g5v0d10v5 | pfet_g5v0d10v5 | PMOS HV | 5V/10.5V | 0.5µm | ~0.90–1.0V | Extended drain DMOS |
Data Source
Simulation data: chennakeshavadasa/gmid_SKY130
ngspice DC sweeps (Vgs step 0.1 mV, W = 2 µm) across 7 device variants and 11–13 channel lengths each.
PDK documentation: skywater-pdk.readthedocs.io
Apache 2.0 licensed. © SkyWater Technology / Google.
Technical Notes
- 400 points per curve, uniformly downsampled from 17.5k–49.5k raw points. This is visually lossless for smooth gm/ID curves.
- Single
index.html with the data embedded. It loads Plotly.js v2.27.0 from a CDN and needs no backend.
- Total file size: ~3.5 MB
- To run it locally, download
index.html and open it in a browser (internet access is needed for Plotly).
License
Tool code: MIT License
Simulation data: see original repo
PDK specs: Apache 2.0 © SkyWater Technology / Google
Related
Built for the open-source silicon community. If you find it useful, please star the repository.
