Crate sindr_devices 

Pure-Rust electronics device physics: linearised companion models for semiconductor and passive components used by MNA-based circuit simulators.

sindr-devices provides the small-signal linearisation that Newton–Raphson solvers need at every iteration: given an applied voltage, each device returns a (g_eq, i_eq) pair — an equivalent conductance and Norton-current source. Stamp those into the MNA matrix and the solver converges on the operating point.

This crate has no dependency on a particular solver. Use it standalone if you’re building your own MNA implementation, or pair it with the companion crate sindr for an end-to-end simulator.

Devices

Module	Device	Model
diode	Silicon diode	Shockley with series resistance + temperature IS scaling
bjt	BJT (NPN/PNP)	Ebers–Moll with Early voltage
mosfet	MOSFET (NMOS/PMOS)	Level-1
jfet	JFET (N/P-channel)	Shichman–Hodges
igbt	IGBT	MOSFET gate control + BJT output conductance
led	LED	Diode with colour-dependent forward voltage
zener	Zener diode	Shockley + reverse-breakdown branch
schottky	Schottky diode	Shockley with low-N, low-IS parameters
varactor	Varactor	Voltage-dependent junction capacitance
thermistor	NTC thermistor	Beta model R(T) = R₀·exp(β·(1/T − 1/T₀))
photodiode	Photodiode	Diode + photocurrent offset
photoresistor	Photoresistor (LDR)	Light-level-dependent resistance

Quick example

use sindr_devices::diode::{DiodeParams, diode_companion};

let params = DiodeParams::silicon();          // IS=1e-14, N=1.0, rs=0.0
let v_applied = 0.65;                          // forward bias, volts
let (g_eq, i_eq) = diode_companion(v_applied, &params);

// Stamp g_eq into Y(p,p), Y(q,q), -g_eq into Y(p,q)/Y(q,p),
// and i_eq into b(p)/-i_eq into b(q) in your MNA system.
assert!(g_eq > 0.0);

Conventions

• Voltages and currents are in SI units (V, A).
• Temperature is in kelvin. Default is 300.15 K (≈ 27 °C, the SPICE default).
• Sign convention for two-terminal companions: v_applied is the voltage from nodes[0] to nodes[1], and i_eq is the current flowing into nodes[0].
• Companion form: each *_companion function returns the linearised (g_eq, i_eq) at the operating point — the form Newton–Raphson stamps directly.

Modules

bjt

BJT (Bipolar Junction Transistor) device model.

diode

Diode model: Shockley equation, companion model, voltage limiting.

igbt

IGBT (Insulated Gate Bipolar Transistor) simplified model.

jfet

JFET (Junction Field-Effect Transistor) device model.

led

LED colour presets.

mosfet

MOSFET Level 1 (Shichman-Hodges) model with body effect.

photodiode

Photodiode companion model.

photoresistor

Photoresistor (LDR) model: resistance as a function of illuminance.

schottky

Schottky diode companion model.

thermistor

NTC thermistor resistance model (Beta model).

varactor

Varactor diode model: voltage-dependent junction capacitance.

zener

Zener diode model: piecewise companion for Newton-Raphson simulation.