IHP gm/ID Design Kit

Analog IC design toolkit using the gm/ID methodology for the IHP SG13G2 130nm BiCMOS PDK.

Features

• Lookup table generator with comprehensive sweep coverage (76 lengths, 13 VBS points)
• Design charts generator for the 4 fundamental gm/ID plots
• Interactive tutorials (Jupyter notebooks in English and Spanish)
• Portable & self-contained - includes vendorized mosplot library
• Color-blind friendly plots using Tol Bright palette

Quick Start

Prerequisites

1. Python 3.9+ with numpy, scipy, matplotlib
2. ngspice installed and in PATH
3. IHP-Open-PDK with PDK_ROOT environment variable set

Installation

git clone https://github.com/Mauricio-xx/ihp-gmid-kit.git
cd ihp-gmid-kit
pip install -r requirements.txt

Generate Lookup Tables

LUT files are not included due to size (~200 MB). Generate them locally:

export PDK_ROOT=/path/to/IHP-Open-PDK

cd src/ihp_gmid
python lookup_generator.py --output-dir ../../data --n-process 4

Generation takes approximately 10-15 minutes.

Using the Lookup Tables

import sys
import os

# Add vendor to path
sys.path.insert(0, os.path.join(os.path.dirname(__file__), 'vendor'))

from mosplot.plot import load_lookup_table, Mosfet

# Load NMOS lookup table
lookup_table = load_lookup_table("./data/sg13_lv_nmos.npz")

# Create Mosfet instance
nmos = Mosfet(
    lookup_table=lookup_table,
    mos="sg13_lv_nmos",
    vbs=0.0,
    vds=0.6,
    vgs=(0.3, 1.2)
)

# Plot gm/ID vs fT
nmos.plot_by_expression(
    x_expression=nmos.gmid_expression,
    y_expression=nmos.transist_frequency_expression,
    filtered_values=nmos.length,
    y_scale="log"
)

Running the Tutorials

cd tutorials/cs_amplifier
jupyter notebook tutorial_en.ipynb  # English
jupyter notebook tutorial_es.ipynb  # Spanish

Repository Structure

ihp-gmid-kit/
├── data/                      # Lookup tables (generated locally)
├── src/ihp_gmid/              # Main package
│   ├── design_charts.py       # Design charts generator
│   ├── lookup_generator.py    # Lookup table generator
│   └── sweep_config.py        # Sweep parameters
├── tutorials/cs_amplifier/    # CS amplifier tutorial
│   ├── tutorial_en.ipynb      # English notebook
│   ├── tutorial_es.ipynb      # Spanish notebook
│   └── design_script.py       # Automated design script
├── vendor/mosplot/            # Vendorized mosplot library
└── examples/                  # Usage examples

Generating Design Charts

cd examples
python generate_design_charts.py

This generates the 4 fundamental gm/ID charts:

• fT vs gm/ID
• Intrinsic Gain (gm/gds) vs gm/ID
• Current Density (ID/W) vs gm/ID
• Transconductance Density (gm/W) vs gm/ID

Lookup Table Coverage

Parameter	Range	Step	Points
VGS	0 to 1.5V	10mV	151
VDS	0 to 1.5V	50mV	31
VBS	0 to 1.2V	100mV	13
Length	0.13 to 9.88 um	130nm	76

Saved parameters: id, gm, gds, vth, vdsat, cgg, cgs, cgd (enables fT calculation).

IHP SG13G2 PDK Notes

Parameter	NMOS	PMOS
Model	sg13_lv_nmos	sg13_lv_pmos
L range	0.13 - 10 um	0.13 - 10 um
W range	0.15 - 10 um	0.15 - 10 um
VDS max	1.5V	-1.5V

License

Apache License 2.0 - See LICENSE

This project includes mosplot (Apache 2.0) - See NOTICE