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passive components

Zener Diode

Computes the series resistor, resistor power dissipation, and zener power dissipation for a zener diode shunt regulator. Assumes a minimum zener current of 10mA.

Inputs

Maximum supply input voltage in volts — used for worst-case power calculations

Minimum supply input voltage in volts — used to size the series resistor

Desired regulated output voltage (= zener voltage) in volts

Load current in milliamps — 10mA minimum zener current is added internally

Results

Minimum input voltage is too low — must be greater than output voltage + 0.8V
ResistanceΩRequired series resistor value in ohms
Resistance PowerWWorst-case power dissipation of the series resistor in watts
Zener VoltageVZener diode voltage — equal to output voltage
Zener PowerWWorst-case power dissipation of the zener diode in watts