A semiconductor that allows current to flow in only one direction. the most common type of diode is a silicon diode. Other diodes include LEDs and photodiodes, which emit and detect light. All diodes are polarized.

Function

Used in circuits as a form of protection to maintain a fixed voltage and protect against voltage spikes.

Sometimes used as a voltage-sensitive switch.

Operating Values

There are two ratings:

1. Voltage
2. Current

Both specify the maximum values that can be applied without damaging the component.