The semiconductor power diode has been used extensively in various power applications such as power rectifiers and power supplies

Diodes Since the invention of semiconductor materials and the eventually birth of the modern day power diode, its usefulness has become apparent to engineers and other electrical designers. As new technology is improving efficiencies and versatility, engineers are finding more ways to use the power diode than ever before.

Outline What is a Power Diode? Sample Power Diodes Schottky Diode Applications of Power Diodes Rectifiers Power Conversion Current Steering (Power Supplies)

Power Diodes A power diode is a crystalline semiconductor device, made primarily of silicon, used mainly to convert alternating current (AC) to direct current (DC), a process known as rectification. Power Diodes work as a one way valve, by conducting current in one direction (the forward direction) while preventing flow in the other direction. Best used in high voltage/high current applications due to their large P-N Junctions & high current carrying capacity. Sample Specs given on following slide from the BYC8-600 Hyperfast Power Diode from NXP Semiconductor

Schottky Diodes The Schottky Diode is a metal–semiconductor whose junction is formed between a metal and a semiconductor, creating a Schottky barrier (instead of a semiconductor– semiconductor junction as in conventional diodes) They are suitable for low voltage very high frequency switching power supply applications Low Forward Voltage Drop ( V at 1mA) Low Junction Capacitance (C) providing high switching speeds.

Rectifiers Used primarily to convert AC to DC. Implemented in high voltage direct current power transmission systems. For power rectification from very low to very high current, semiconductor diodes of various types ( Schottky diodes, etc.) are widely used.

Power Conversion Rectifiers are constructed from diodes, where they are used to convert alternating current (AC) electricity into direct current (DC). Automotive alternators are a common example, where the diode, which rectifies the AC into DC, provides better performance than the commutator or earlier, dynamo.

Current Steering Using diodes, you can prevent current from flowing in unwanted directions. A power supply can use this to ensure that power is only drawn from a battery when necessary. In automotive use, a heavy-duty split-charge diode is used to prevent the engine battery from discharging through the lower-charge battery when the alternator is not running.

Conclusion Power Diodes have a multitude of uses in power applications. The Shottky Diode is a common power diode. Rectifiers use power conversion for converting AC to DC in most high power applications. Current steering can be used from laptop power supplies to automotive applications.

References Donald Neaman, (2003) Semiconductor Physics & Devices", pp.331 – 333 Anonymous. Schottky_diode_symbol.svg. Wikipedia. Anonymous. Rectifier.jpg. Wikipedia. Shimada, N. High-Power 625-nm AlGaInP Laser Diode. Dec NXP Semiconductors. t_recovery/

Concepts What is a Power Diode… Primary uses of a Power Diode Schottky Diodes Power Conversion Current Steering