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What happens if the maximum voltage is exceeded for a diode?
The forward voltage is the amount of voltage needed to get current to flow across a diode. If this power exceeds the wattage rating of the diode, you will soon see the magic smoke come out and the diode will be toast.
How much voltage does a diode use?
In a small silicon diode operating at its rated currents, the voltage drop is about 0.6 to 0.7 volts. The value is different for other diode types—Schottky diodes can be rated as low as 0.2 V, germanium diodes 0.25 to 0.3 V, and red or blue light-emitting diodes (LEDs) can have values of 1.4 V and 4.0 V respectively.
What happens if you exceed maximum voltage?
Exceed the voltage, and the resistive components can overheat or draw too much current. The insulation may not be able to stop induction from the higher voltage, or may break down completely. Transformers and voltage regulators will malfunction if they cannot handle the excessive voltage.
Which is the maximum current that a Zener diode can handle?
IZM is the maximum current that can flow through the zener diode, PZM is the maximum power that the zener diode can handle, and VZ is the zener voltage. So if a zener diode has a zener voltage of 5.1V and a power rating of 1W, it can handle 1W/5.1V ma, which is approximately 196mA of current.
How do you determine the size of a diode?
Also determine the maximum voltage the diode will have across it in the reverse direction—positive voltage to cathode, negative voltage to anode. If the circuit uses DC only, you can size the diode by taking these voltage and current values and adding 20 to 50 percent for safety.
Which is the highest voltage a diode can tolerate?
PIV is the highest voltage a diode can tolerate in a reverse-bias direction. Maximum forward current is the most current the diode can conduct in the forward direction. Generally, larger PIV and currents mean physically larger, more expensive diodes. Sizing a diode means finding one that best suits the circuit for a reasonable price.
How big of a safety margin do you need for diodes?
As with the other ratings, you’ll want to allow at least a 20 percent safety margin. Note the diode’s packaging or case style. Larger diodes will dissipate more heat, so they’ll be packaged with a metal heat-sink tab. Even larger diodes will look like metal bolts, meant to attach firmly to large conductors and heat sinks.