Zener Diode Circuit Design Calculator

Zener Diode Circuit Design Calculator

Calculate the series resistor for a Zener diode regulator using: $$ R = \frac{V_S – V_Z}{I_Z + I_L} $$

* Currents are entered in mA (converted to A internally). Use SI units throughout.

Step 1: Enter Circuit Parameters

e.g., 12 V

e.g., 5.1 V

e.g., 5 mA

e.g., 0 mA if no load is present

Series Resistor: $$ R = \frac{V_S – V_Z}{(I_Z + I_L)/1000} $$
Resistor Power: $$ P_R = \frac{(V_S – V_Z)^2}{R} $$
Zener Diode Power: $$ P_Z = V_Z \times \frac{I_Z}{1000} $$