Constant-current diode
A constant-current diode is an electronic device that limits current to a maximal specified value for the device. It is known as a current-limiting diode (CLD) or current-regulating diode (CRD).
It consists of an n-channel JFET with the gate shorted to the source, which functions like a two-terminal current limiter or current source (analogous to a voltage-limiting Zener diode). It allows a current through it to rise to a certain value, and then level off at a specific value. Unlike Zener diodes, these diodes keep the current constant instead of the voltage constant. These devices keep the current flowing through them unchanged when the voltage changes.
Note that some devices are unidirectional and voltage across the device must have only one polarity for it to operate as a CLD, whereas other devices are bidirectional and can operate properly in either polarity.
Wide-bandgap materials such as silicon carbide have been used in production devices to enable high-voltage applications in the kilovolt range.[1]
References
- "CALY Technologies SiC CLD devices". CALY Technologies. Retrieved 26 April 2020.
External links
- IEEE 315 symbol for current-regulating diode
- Advantages of Constant Current Regulators (CCR) in Driving LEDs on YouTube
- Diode
- CLD diode datasheet, MCC
- CRD diode datasheet, Semitec
- J500 diode datasheet, Linear Systems / Siliconix / Vishay
- 1N5283 to 1N5314 diode datasheet, Central Semiconductor
- JFET
- 2N5457/8/9 & MMBF5457/8/9 JFET datasheet, ON Semiconductor (Former Fairchild)