Struct OpAmpModel 

pub struct OpAmpModel {
    pub open_loop_gain: f64,
    pub gbw: f64,
    pub slew_rate: f64,
    pub v_rail_pos: f64,
    pub v_rail_neg: f64,
    pub output_impedance: f64,
    pub output_capacitance: f64,
}

Op-amp model parameters for WDF integration.

Models the op-amp as a voltage-controlled voltage source: Vout = Aol * (Vp - Vm)

Where:

• Aol is the open-loop DC gain (typically 100k-1M)
• Vp is the non-inverting input voltage (set externally)
• Vm is the inverting input voltage (often feedback-dependent)

The feedback network stays in the WDF tree as passive components. The op-amp root enforces the gain relationship between its differential input and output via Newton-Raphson iteration.

Non-idealities captured:

• Finite open-loop gain
• Output voltage saturation
• Slew rate limiting (optional, applied post-convergence)
• Gain-bandwidth product (closed-loop bandwidth rolloff)

Fields

open_loop_gain: f64

Open-loop DC gain. TL072 ≈ 200k (106dB), LM308 ≈ 300k.

gbw: f64

Gain-bandwidth product (Hz). TL072 ≈ 3MHz, LM308 ≈ 1MHz. Determines closed-loop bandwidth: f_cl = GBW / closed_loop_gain.

slew_rate: f64

Slew rate (V/µs). TL072 ≈ 13, LM308 ≈ 0.3.

v_rail_pos: f64

Maximum positive output swing (V above bias point). For symmetric bias: same as v_rail_neg. For asymmetric: differs.

v_rail_neg: f64

Maximum negative output swing (V below bias point).

output_impedance: f64

Output impedance (Ω). Typically 50-200Ω for voltage-feedback op-amps. Used by the VCVS stamp in the MNA nullor path.

output_capacitance: f64

Output capacitance (F). Physical capacitance of the output stage. Keeps the output node as a dynamic state in the state-space reduction, preserving the feedback loop’s energy recirculation. Typical: 10-50pF.

Implementations

impl OpAmpModel

pub fn tl072() -> OpAmpModel

TL072 — JFET-input dual op-amp.

The modern standard for guitar pedals. Fast slew rate (13 V/µs), low noise, high input impedance. Used in Klon Centaur, Phase 90, and countless modern designs.

pub fn tl082() -> OpAmpModel

TL082 — JFET-input dual op-amp (TL072 variant).

Similar to TL072 but slightly different specs. Used interchangeably in many designs.

pub fn lm308() -> OpAmpModel

pub fn lm741() -> OpAmpModel

pub fn jrc4558() -> OpAmpModel

pub fn rc4558() -> OpAmpModel

pub fn ne5532() -> OpAmpModel

pub fn op07() -> OpAmpModel

pub fn generic() -> OpAmpModel

Trait Implementations

impl Clone for OpAmpModel

fn clone(&self) -> OpAmpModel

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for OpAmpModel

impl Debug for OpAmpModel

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.