Constant current diode
Encyclopedia
Constant current diode consists of a JFET
with the gate shorted to the source, and it functions like a two-terminal current limiter or current source
(analog to 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 instead of keeping the voltage constant, keeps the current constant. These devices keeps the current flowing through them unchanged when the voltage changes.
JFET
The junction gate field-effect transistor is the simplest type of field-effect transistor. It can be used as an electronically-controlled switch or as a voltage-controlled resistance. Electric charge flows through a semiconducting channel between "source" and "drain" terminals...
with the gate shorted to the source, and it functions like a two-terminal current limiter or current source
Current source
A current source is an electrical or electronic device that delivers or absorbs electric current. A current source is the dual of a voltage source. The term constant-current sink is sometimes used for sources fed from a negative voltage supply...
(analog to voltage limiting Zener diode
Zener diode
A Zener diode is a special kind of diode which allows current to flow in the forward direction in the same manner as an ideal diode, but will also permit it to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage, "Zener knee voltage" or "Zener...
). 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 instead of keeping the voltage constant, keeps the current constant. These devices keeps the current flowing through them unchanged when the voltage changes.
External links
- http://www.avtechpulse.com/faq.html/IV.5/
- http://www.atcsemitec.co.uk/pdfdocs/SemitecCRDs.pdf