Silicon Carbide Schottky Diodes (SCSDs) are wide band gap semiconductor devices widely employed in power electronics. Offering higher performance and more energy-efficiency compared to conventional silicon devices, SCSDs provide better overall power conversion efficiency than their silicon counterparts.
Galaxy Microelectronics’ 650V and 1200 V SiC Schottky diodes are perfect for hard-switching applications, offering lower forward voltage drop and faster recovery than silicon models.
High Breakdown Voltage
Silicon Carbide (SiC) Schottky diodes are wide bandgap semiconductor devices used in power electronics. Applications include electric and hybrid vehicles, solar cells, radio frequency detectors and rectifier circuits; among others. Their main characteristics are high breakdown voltage, low forward voltage drop and fast recovery time; with their high temperature operation also permitting increased switching speeds that help minimize power losses and maximize efficiency.
SiC Schottky barrier diodes consist of metal contacts made up of either platinum (Pt) or titanium (Ti), mounted to an n-type SiC semiconductor material and connected by metal leads – typically platinum (Pt) or titanium (Ti). The metal contacts create an effective Schottky barrier, restricting current to only flow one way through it; this allows large current flows through without creating losses – ideal for high efficiency/power efficient devices.
SiC Schottky diodes, as wide bandgap semiconductors, feature higher breakdown electric fields than their silicon (Si) counterparts and thus are suitable for applications requiring high power and frequency such as electric vehicle drives, PV inverters and power supplies. Furthermore, SiC diodes boast both increased breakdown electric fields as well as lower on-state resistance compared to their Si-based counterparts.
Wolfspeed’s end-to-end production capability enables us to craft SiC diodes that provide exceptional performance for use in power electronics designs, ready for integration. Our range of current ratings, voltage ratings and packaging options allows us to produce diodes tailored specifically to each application.
Low Forward Voltage Drop
One of the greatest advantages of a silicon carbide schottky diode lies in its ability to deliver lower forward voltage drops than traditional silicon designs, leading to less wasted energy as heat. Furthermore, this feature enables higher frequencies for improved performance and efficiency.
Silicon carbide diodes are made possible due to being “majority carrier” semiconductor devices, meaning that when in normal operation only n-type electrons will freely move across their junction and join metal contact. When reverse biased however, p-type electrons will also have access to join current flow and allow an early cessation of current flow than with traditional p-n junction rectifiers.
Silicon carbide schottkys’ fast switching speeds can significantly lower power loss in an electronic circuit design. Furthermore, their smaller magnetic and passive components enable designers to reduce overall size as well as production cost of final electronics systems.
Silicon carbide schottkys have the added advantage of providing extremely low leakage current levels due to their ultra low resistance and higher breakdown voltage. Leakage current levels are therefore reduced significantly compared with traditional silicon schottky diodes, helping electronic designs shrink while improving efficiency.
Silicon carbide schottky diodes offer significantly higher maximum reverse voltage protection than their silicon counterparts; in some instances up to one kilovolt or higher depending on the diode in question. Nexperia SiC offers a hybrid diode design called the ‘merged PiN Schottky”, which incorporates both silicon carbide schottkys as well as standard P-N diodes in parallel in order to provide extra surge voltage protection.
Fast Recovery Time
Silicon carbide schottky diodes can stop current flow much more quickly than their silicon counterparts due to some nontrivial quantum physics. When reverse biased, a Schottky diode acts much like an one-way valve: when electrons flow backwards through its conduction band and are rapidly injected back into it again and released for free flow again, virtually instantly stopping current. This contrasts greatly with random recombination between n and p carriers that happens with standard diodes which occurs over time compared with slow random random recombination between n and p-type carriers in standard diodes which takes much longer.
Rapid recovery time makes this device suitable for applications where high-speed switching is necessary and reduces stress on other components within the circuit. Furthermore, its fast recovery time results in smaller overall device size while permitting more power transmission within each package.
WeEn offers an impressive selection of standard and custom silicon carbide Schottky diodes in D2PAK, TO-247 and insulated TO-220AB/AC packages, offering unrivaled reverse voltage drop, forward current capability and temperature coefficient ratings up to 1200 V. Additionally, MPS (merged PN Schottky) designs take advantage of its natural durability to deliver lower leakage current levels and enhanced surge capabilities.
WeEn is dedicated to quality and reliability, evidenced by our rigorous product testing procedures. For example, all SiC diodes undergo 100% static parameters testing as well as surge current handling testing and avalanche capability evaluation in order to guarantee our customers receive maximum performance from their diode solutions.
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Silicon carbide Schottky diodes offer low leakage current even when reverse biased. This allows smaller diodes to provide higher output ratings while simultaneously reducing circuit board size and weight.
Low leakage current is also crucial when used for applications requiring fast switching speeds, such as in buck boost converters or other switched power supply applications. Here, diodes must quickly turn on and off without losing energy during its switching cycles; hence making these devices ideal for high speed switching applications such as those found in switched power supplies.
SiC schottky diodes feature narrow depletion zones to mitigate parasitic effects such as ringing and other capacitive noise, making them especially suitable for use in RF power applications.
SiC diodes are created through epitaxial growth and wafer bonding techniques, beginning with a thin metal layer bonded to an N-type doped semiconductor (the M-S junction), before merging these layers to form the Schottky barrier that gives this type of diode its name.
Due to their wide bandgap semiconductor material, these diodes possess much higher current densities compared to standard P-N diodes and therefore can handle much higher current without decreasing power efficiency compared to their silicon counterparts.
Due to their wide temperature operating range and high voltage breakdown capabilities, these devices are quickly gaining in popularity across a range of electronic design applications, such as buck-boost converters, photovoltaic solar inverters, electric vehicle chargers and other high-voltage power supplies.
As wide-bandgap semiconductors operate at high temperatures, they must undergo extensive reliability testing to ensure their stability. This testing includes 100% static parameters testing, 100% surge current handling testing (IFSM), and 100% avalanche capability testing (UIS). WeEn has established comprehensive quality and reliability control systems which enable us to manufacture some of the highest-quality power semiconductors currently available on the market today.
High Temperature Operation
Silicon carbide Schottky diodes have the unique capability of operating at higher temperatures than their silicon counterparts while still maintaining high levels of performance. This is due to the inherent durability of silicon carbide which aids it to conduct current more efficiently, thus reducing heat generation within the device that could otherwise lead to an unexpected resistance increase or thermal runaway.
SiC schottky barriers feature wide band-gap semiconductor characteristics that enable it to offer lower turn-on voltage than its PN junction counterpart, enabling faster on/off cycles and thus increased switching speeds within electronic circuits. This feature can help reduce power losses while simultaneously permitting smaller magnetic and passive components within circuits.
Silicon carbide schottky diodes boast lower turn-on voltages and forward voltage drops than their silicon equivalents due to wide band-gap semiconductor materials providing more efficient conductivity, thus decreasing voltage drop across barriers.
Nexperia’s buried grid silicon carbide Schottky diodes feature an internal parasitic p-n diode to prevent thermal runaway and allow a much quicker recovery time than conventional silicon-based diodes. This diode acts as a distributed ballasting resistor to diffuse current load over a wider area and avoid localized thermal runaway events.
Alter Technology has developed a line of hermetically metal-ceramic packaged silicon carbide diodes designed to meet power space applications, featuring junction temperatures up to -170oC/280oC with excellent long-term stability and reverse leakage characteristics under such extreme conditions. These devices can be found in applications requiring high efficiency/reliability such as hard-switching power supplies or solar array protection diodes.