Advantages of Silicon Carbide Diodes

Silicon carbide (SiC) is a wide bandgap semiconductor found naturally as moissanite jewels and mass produced as powder or crystal to be used as an abrasive.

SiC Schottky Diodes are ideal for power conversion applications, providing advantages over conventional silicon diodes. Read on to discover their key benefits:.

Faster switching speed

Silicon unipolar diodes have an upper limit of 150 V due to their high on-state resistance and leakage current; in comparison, SiC Schottky diodes offer much lower specific on-state resistance and much higher blocking voltage, providing faster switching speed in power electronics devices.

SiC is known for its wide bandgap that allows transistors to easily handle higher electric fields, enabling quicker and more reliable switching operations. Furthermore, their lower specific on-state resistance contributes to lower energy losses at higher speeds for increased switching performance.

SiC MOSFETs’ lower on-state resistance and faster switching speeds also enable designers to improve efficiency by using smaller components on the PCB – perfect for space-constrained applications.

SiC devices take advantage of high field carrier drift velocity to quickly remove minority charges from their drift region, which leads to faster switching speed and reduces BOM costs by eliminating snubber circuits in power electronics designs.

Snubber circuits are energy-absorbing circuits designed to absorb voltage spikes caused by switching diodes on or off. While necessary in many applications, snubber circuits add complexity and cost by necessitating additional components like resistors and capacitors that increase system size.

GeneSiC’s trench-assisted planar gate technology delivers industry-leading RDS(ON) and switching speed in an extremely compact and rugged package, providing maximum reliability for critical applications such as electric vehicle charging, solar inverters, data center/telco power supplies and energy storage systems. These devices can withstand the extreme temperatures found in these applications without increasing footprint size or diminishing system reliability – an excellent solution to increase power density without decreasing footprint size or system uptime.

Lower forward voltage drop

Silicon carbide diodes have much lower forward voltage drops compared to their silicon counterparts, allowing for higher current flows through smaller devices while decreasing power dissipation as well as decreasing component size and weight.

Schottky barrier diodes feature lower intrinsic forward resistance than traditional silicon unipolar power devices, leading to reduced forward voltage drop. Their structure includes metal contacts fabricated from platinum (Pt) or titanium (Ti) on an n-type SiC semiconductor material which create a rectifying contact between anode and cathode, permitting current to flow only one way.

Silicon carbide power devices’ high-speed capability also enables them to reduce snubber circuit requirements in certain applications, leading to reduced system costs and greater efficiency.

Silicon carbide power devices offer significant reliability advantages for various applications. Silicon carbide body diodes in particular have the capacity to withstand higher temperatures than their conventional power MOSFET counterparts and bipolar transistors, enabling higher switching frequencies without increasing power losses or heat generation.

Nexperia’s MPS silicon carbide power devices deliver higher switching speeds, better thermal conductivity and reduced forward voltage drop when compared with previous-generation solutions. Furthermore, their recovery times and reverse leakage current are considerably faster – enabling more energy transfer from anode to cathode during normal operations.

These devices come in both through-hole and surface mount packages ranging from 4 A to 40 A with options for various temperatures. In order to ensure robustness in demanding power fields, these products have passed both higher temperature reverse bias testing as well as temperature cycling tests.

Higher current-carrying capacity

Diodes are fundamental semiconductor devices that permit current to flow in one direction while restricting it in another direction, making them one of the most revolutionary inventions ever. Diodes are present in virtually all electronic components and have numerous uses ranging from power supplies converting AC energy to DC for use, to AM radio signal peak detection, to creating basic logic gates.

SiC Schottky diodes operate using a metal-semiconductor junction known as the Schottky barrier. When metal (typically aluminum or platinum) is deposited on SiC surface, this forms a Schottky barrier, which allows current to pass in either direction through diode. Unlike P-N junction diodes that feature a depletion region, SiC diodes offer much thinner Schottky barriers resulting in greater current carrying capacities and current carrying capabilities than P-N junction diodes do.

Schottky diodes produce large amounts of heat when exposed to high current, leading them to generate significant joule heat and cause the device to heat rapidly – this phenomenon is known as the hot carrier effect and could ultimately lead to device failure if left unmanaged properly.

Nexperia provides SiC Schottky Diodes that have been specifically engineered for maximum performance and reliability to reduce this risk, offering lower reverse current spikes than traditional silicon diodes and zero recovery switching with lower switching loss for optimized power conversion circuit efficiency. Together with Nexperia’s superior figure-of-merit (Qc x VF), this gives designers unparalleled power conversion performance applications.

Higher breakdown voltage

Silicon carbide diodes feature high breakdown voltages that enable designers to use them in power applications with higher currents and can be switched at higher temperatures for increased efficiency in designs.

Wide bandgap semiconductor technologies like SiC are becoming more and more prevalent for use in power electronics applications, prompting manufacturers to increase the frequency and duration of endurance tests to ensure these devices will survive under harsh conditions and continue operating reliably for extended periods.

These tests typically involve high-temperature exposure and severe current cycling to examine how well a device handles repeated cycling and temperature extremes without failing. Based on its performance during these tests, its suitability for specific applications may be determined or improvements should be made accordingly.

As demand for wide bandgap semiconductor devices increases, engineers are searching for ways to reduce both cost and size while maintaining reliability. One approach is replacing silicon-based power components with silicon carbide (SiC) Schottky diodes whose higher blocking voltage allows designers to build smaller yet more effective systems.

In order to achieve a high blocking voltage, SiC devices need n layers that are 10 times thinner than silicon diodes with lower specific on-state resistance and greater donor density.

Microsemi provides an expansive portfolio of Silicon Carbide power Schottky barrier diodes suitable for high voltage applications, including singles, duals and bridges in various packages. These Schottky diodes are suitable for applications including:

Better thermal conductivity

Silicon Carbide Diodes and Transistors benefit from superior thermal conductivity to dissipate heat efficiently at higher temperatures, thus helping reduce power losses while expanding its operating temperature range. As a result, silicon carbide devices are ideal for power applications where operating at elevated temperatures without impacting reliability is critical.

SiC Schottky barrier diodes work on the basis of the Schottky barrier junction, a metal-semiconductor junction created when aluminum or platinum is deposited over a SiC substrate to form a Schottky barrier. As there is no depletion region present like in traditional P-N diodes, forward voltage drop and switching speed are reduced significantly and switching is faster.

SiC diodes are more resistant to heat than their silicon counterparts, making them a reliable choice for applications that may be susceptible to damage from transient thermal events such as data centers that utilize drastic measures to protect servers such as submerging them in saltwater or covering them with snow for heat protection.

Nexperia’s advanced SiC fast recovery diodes feature an innovative design that removes the need for snubbers across their devices, which could otherwise cause ringing and oscillations when used in high frequency power designs. Furthermore, their higher current carrying capacity and greater breakdown voltage make them suitable for operating at higher frequencies and temperatures than standard silicon diodes.

Silicon carbide (SiC) offers many advantages to power applications, from improved efficiency and reliability to higher power density in similar packages. Wolfspeed experts are on hand to assist with selecting suitable SiC MOSFETs and Schottky diodes for any given application.