Constant-current diode
Constant-current diode is an electronic device that limits current to a maximum specified value for the device. It is known as current-limiting diode (CLD), current-regulating diode (CRD).
These diodes consist of a n-channel JFET-transistor 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). They allow a current through them 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. An example is the 1N5312. Note the negative VGS is required, as an example on the n-type junction-gate field-effect transistor 2N5457.
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
- 1N5283 to 1N5314 diode datasheet, Central Semiconductor
- JFET
- 2N5457 & MMBF5457 JFET datasheet, Fairchild