Zener diode

Diode with reverse breakdown at Bv.

  • electrical
  • Modelica Standard Library
  • 2 ports
  • 1 parameter
BlockZener diodeKindzenerDiodeLibrarySemiconductors

Description

A diode with three regions: exponential forward conduction, a leakage region, and exponential reverse breakdown near −Bv. Use it for voltage references and clamps.

Example

Diodes and a Zener regulator Three diode models rectifying a 10 V sine, and a Zener diode holding 5.1 V.

10 V 50 Hz ADiodeLoad Av AGround A10 V 50 Hz BIdeal diodeLoad Bv BGround B10 V 50 Hz CDiode (exponential)Load Cv CGround C12 VR 100 ΩZener 5.1 Vv ZenerGround (Zener)
In Gradara, select a Zener diode block and press F1, then choose Open example. It opens as a new model in My models, ready to run.

Also in this example:DC voltageVoltage sensorGroundResistorDiodeAC voltageIdeal diodeDiode (exponential)

Ports

Conserving terminals 2

  • +pelectrical

    Anode. Current into p is counted as positive (forward). In breakdown, current flows from n to p.

  • −nelectrical

    Cathode. Connect it to the more positive node for Zener operation.

Parameters

  • Breakdown voltageBv5.1 V

    ≥ 0

    Breakdown voltage, in volts, as a positive number: the reverse voltage at which the breakdown current reaches 0.7 A.

Equations

Modelica
v = p.v − n.v, i = p.i
i = Ids · (exp(v / Vt) − 1) − Ibv · exp(−(v + Bv) / (Nbv · Vt)) + v / R
Fixed: Ids = 1 µA, Vt = 0.04 V, Ibv = 0.7 A, Nbv = 0.74, R = 100 MΩ
Both exponentials continue linearly beyond 30 times their scale voltage.

Implementation

Modelica Standard Library 4.1.0Modelica.Electrical.Analog.Semiconductors.ZDiode
MSL documentation

Assumptions and limitations

  • Only Bv is adjustable. The knee current Ibv = 0.7 A is large, so at milliampere currents the clamp voltage is about 0.2 V below Bv.
  • No temperature dependence, capacitance, or dynamic resistance setting.

See also

Select a block in Gradara and press F1 to open its page offline.