Chip Diode can be called a crystal diode, commonly known as the diode (diode), which is a one-way conductive electronic devices. Inside the Chip Diode has a PN junction two lead terminals, the electronic components in accordance with the direction of the applied voltage, the current can be sent in one direction. In general, the SMD diodeis a p-n junction formed by sintering p-type and n-type semiconductors. In this interface on both sides of the formation of space charge layer, constitute a self-built electric field. When the applied voltage is equal to zero, the concentration difference of carriers on both sides of the p-n junction causes the diffusion current to equalize with the drift current caused by the self-built electric fieldand is in an electrical equilibrium state, which is also the diode characteristic under normal conditions.
What are the classification of SMD diodes?
1, according to the semiconductor used can be divided into:
(1) germanium Chip Diode (Ge tube)
(2) silicon Chip Diode (Si tube)
2, according to the core tube plan, you can be divided into:
(1) contact patch diode - point contact type patch diode is a very thin metal wire pressure in the bright semiconductor chip appearance, through the pulse current, so that one end of the wire with the chip firmly sintered together, Form a "PN junction." From the point of contact, allowing only a smaller current, suitable for high frequency and low current circuits, such as the radio detector.
(2) Surface Contact Patch Diodes - Surface-Contact SMD diodes have a large "PN junction" area that allows large currents to flow and is primarily used in "rectification" circuits that convert AC power to DC power.
(3) Planar contact patch diode - Planar patch diode is a special silicon Chip Diode, it can not only through a larger current, and the function of stable and reliable, and more for switching, pulse and high frequency circuits .
3, according to different uses and can be divided into:
(1) detection Chip Diode
(2) rectifier Chip Diode
(3) regulator Chip Diode
(4) switch Chip Diode
(5) silicon power switch Chip Diode
(6) blocking Chip Diode
(7) Schottky Chip Diode
(8) light emitting diode chip (LED Chip Diode)
(9) rotating Chip Diode
(10) Transient Voltage Suppression SMD Diode (TVS Tube)