Diode Forward Voltage Calculator
Estimate the voltage remaining after a diode drop in a circuit. Enter supply voltage, diode forward voltage, and load current.
V
V
mA
Output Voltage
4.30 V
Diode Power Dissipation70.0 mW
Output Voltage vs Supply Voltage
Diode Forward Voltage Drop
When current flows through a diode, it drops a nearly constant forward voltage V_f.
Formula
V_out = V_supply - V_f
P_diode = V_f x I_load
Silicon diodes drop about 0.7 V, Schottky diodes 0.2-0.4 V, and LEDs 1.8-3.3 V depending on color.
Example Calculation
A silicon diode (0.7 V drop) in a 5 V circuit carrying 100 mA.
- 01V_out = 5 - 0.7 = 4.3 V
- 02I_load = 100 / 1000 = 0.1 A
- 03P_diode = 0.7 x 0.1 = 0.07 W = 70 mW
Frequently Asked Questions
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Ohm's Law Guide
A complete guide to Ohm's Law. Learn the relationship between voltage, current, and resistance, with practical examples, the power triangle, and circuit analysis tips.