pulp::signal::junction Namespace Reference

Classes
struct	JunctionPair
	One junction network: the exponential law over one or two antiparallel legs. More...

Functions
double	safe_exp (double x)
	exp(x) with the argument clamped into the safe range.
double	exprel (double x)
	(exp(x) − 1) / x, with the removable singularity at 0 handled.

Variables
constexpr double	kThermalVoltage = 0.02585
	Thermal voltage k·T/q at 300 K, in volts.
constexpr double	kMaxExponent = 80.0
	Ceiling on an exponent argument, so a transient overshoot cannot produce inf.

Function Documentation

exprel()

double pulp::signal::junction::exprel ( double x )

inline

(exp(x) − 1) / x, with the removable singularity at 0 handled.

Two Taylor terms are already below double precision at the cutoff, so the branch is exact rather than approximate where it matters.

safe_exp()

double pulp::signal::junction::safe_exp ( double x )

inline

exp(x) with the argument clamped into the safe range.

Variable Documentation

kMaxExponent

double pulp::signal::junction::kMaxExponent = 80.0

inlineconstexpr

Ceiling on an exponent argument, so a transient overshoot cannot produce inf.

exp(80) ≈ 5.5e34 is far past any current a real collector load will admit, and well short of exp's overflow near 709.

kThermalVoltage

double pulp::signal::junction::kThermalVoltage = 0.02585

inlineconstexpr

Thermal voltage k·T/q at 300 K, in volts.

A physical constant derived from k/q = 8.617e-5 V/K, not a fitted value.