SYCAN

SYmbolic Circuit ANalysis: a SymPy-backed netlist solver that produces closed-form DC operating points, AC transfer functions, small-signal impedance, and noise spectral densities.

Try it in your browser

A live REPL with worked examples runs entirely in the browser via Pyodide — no install required.

👉 Launch the sycan REPL demo

Want to draw circuits instead of typing them? Capture schematics on a snap-grid canvas and export a netlist:

👉 Launch the sycan circuit editor

Contents

• Getting started
  • Install
  • Build a circuit
  • DC operating point — solve_dc()
  • AC transfer functions — solve_ac()
  • Port impedance — solve_impedance()
  • Noise PSD — solve_noise()
  • Draw a schematic — autodraw()
  • What next
• Examples
  • DC divider with numeric substitution
  • Second-order low-pass transfer
  • Input impedance of a loaded node
  • Render a quick schematic
• Assumption engine
  • The four assumption types
  • Limit — collapsing free symbols
  • MuchGreater / MuchLess — relative magnitudes
  • Approximate — pin without a limit
  • Region — declare the operating region, then verify
  • Attaching vs. passing assumptions
  • The unified solver
  • Checking the assumptions
  • Worked example: amp design with intent baked in
  • Try it in the REPL
  • See also
• How autodraw works
  • Pipeline at a glance
  • The component model: spine and side ports
  • Glyph loading
  • Tweaking the visual density
  • Pattern-detect overrides (autodraw_hacks)
  • Function reference
• Component glyphs
  • Adding a custom glyph
• SYCAN terminology reference
  • 1. Physical constants
  • 2. MOSFET parameters
  • 3. BJT (Gummel-Poon) parameters
  • 4. Diode (Shockley)
  • 5. JFET (Shichman-Hodges depletion-mode)
  • 6. Vacuum-tube triode (Langmuir 3/2 power)
  • 7. Voltage-controlled passive devices
  • 8. Mutual inductance (MutualCoupling)
  • 9. Transmission line
  • 10. Controlled sources (basic two-port primitives)
  • 11. Behavioral sources (B-element)
  • 12. Signal-flow blocks (sycan.components.blocks)
  • 13. SubCircuit (sycan.components.blocks.subcircuit)
  • 14. Voltage source waveforms (VoltageSource)
  • 15. MNA & analysis terms
  • 16. ERC / DRC (sycan.check)
  • 17. Network parameters (sycan.network_params)
  • 18. Noise
  • 19. Filter prototypes (sycan.polynomials)
  • 20. Headroom analysis (sycan.headroom)
  • 21. Acronym quick-reference
• API reference
  • Common entry points
  • Full module reference

New here? Start with Getting started for an installable end-to-end walk-through of every solver plus autodraw().

Indices

• Index

• Module Index

• Search Page