Efabless Logo
public project

PDK, Tools & Pre-requisites Installation

In order to get the caravel_fulgor_opamp project running several tools and files need to be installed. To simplify the installation and to make sure you fullfill all the pre-requisites an install_pdk.sh script is provided. To run the script just type on the console:

bash ./install_pdk.sh

This script does the following: - Installs all the packages needed to use the opensource tools and the Google-Skywater 130nm Open Source PDK - Clones & installs the Google-Skywater 130nm Open Source PDK - Installs the schematic caputre tool XSCHEM - Installs XSCHEM symbol library for the Google-Skywater 130nm Open Source PDK. - Installs the simualtion engine ngspcie - Installs the layout desing tool magic - Installs the layput desing tool klayout - Installs the LVS check tool netgen - Installs the Open_PDKs - Installs the pre-check tool for the Efabless/Skywater/Google Caravel project.

General Purpose Open Source Operational Amplifier (OpAmp)

This project is a test chip, which contains several two stages operationals amplifiers with Miller compensation. This is an all analog desing implemented on the Google-Skywater 130nm Open Source PDK. It is an Open Source project underApache License 2.0.

The OpAmp desing is located in an Open Source SoC Harness obtained from the efabless Caravel Project.

Running the Tools


To run xschem and be able to simulate the OpAmp's test benches the following commands need to be run:

bash cd caravel_fulgor_opamp/xschem xschem In the xschem folder it is found the xschemrc file, where the paths to the xschem libraries are defined.


To run magic and be able to edit or desing a layout the following commands need to be run:

bash cd caravel_fulgor_opamp magic -rcfile mag/dh.magicrc The dh.magicrc file specifies where the open_pdk layout libraries are located. If magic is used without the -rcfile specification, the sky130 library won't be loaded.

OpAmp Desing

General Specifications:

  • Vdd = 1.8V
  • Iref = 100uA
  • Power Consumption = ~2.7uW
  • DC Gain = ~20dB Closeloop
  • Bandwidth = 40MHz
  • Output Noise = ~300uV


project layout image
project layout image
Layout Image

Operational amplifier (opamp) based on the Miller topology designed in Skywater SKY130 CMOS process.




Analog Integrated Circuit Design