Xschem — The Complete Guide: Free Hierarchical Schematics for Analog and Mixed-Signal Circuits
Xschem is a program for drawing hierarchical electrical schematics, aimed mainly at analog and mixed-signal integrated-circuit design. Its drawing engine is written in C and is very fast, and it is widely used in open chip design flows alongside ngspice and Magic.
Xschem
Stefan Schippers
Hierarchical schematic capture for analog and mixed-signal circuits, with SPICE, Verilog and VHDL netlist output.
Get it from the vendorWhat you get
- Hierarchy — blocks within blocks, with unlimited drawing size.
- Parametrised components — values and sizes carried into the netlist.
- Netlists — SPICE, Verilog or VHDL for simulation.
- Plots in the schematic — simulation results shown directly in the drawing.
- Tcl extensions — automation and your own tools.
Who it suits
Analog chip designers and students working with open process design kits. For ordinary printed circuit boards, a PCB tool such as KiCad is a better fit. Xschem is developed mainly for Linux, and separate binary builds exist for Windows. It is licensed under GPL-2.0.
Related tools
For simulating the netlist — ngspice. For the physical layout of the circuit — Magic VLSI. For a parallel SPICE simulator for large circuits — Xyce.
Ngspice
Ngspice Project
Open-source SPICE simulator — DC, AC, transient and noise. The engine behind KiCad simulation.
Get it from the vendor
Magic VLSI
Tim Edwards (Open Circuit Design)
A veteran chip layout editor with real-time design-rule checking, parasitic extraction and GDS and LEF/DEF support.
Get it from the vendor
Xyce — Parallel Analog Circuit Simulator
Sandia National Laboratories
Sandia National Laboratories’ SPICE simulator, built for very large circuits and parallel execution.
Get it from the vendor
KLayout
Matthias Köfferlein
Viewer and editor for chip mask layouts (GDS2, OASIS) — fast even on huge files, with DRC, LVS and scripting.
Get it from the vendorThe bottom line
Xschem is the usual starting point for open-source analog chip design: from schematic to simulation, fast and free.