Advantages of Using a Silicon Carbide Diode in Power Electronics

Silicon carbide (formerly Carborundum) has become increasingly important for use in power electronics applications, particularly with Schottky barrier diodes.

SiC Schottky diodes consist of a metal-semiconductor junction where only electrons flow, rather than holes as in traditional PN junction diodes.

These devices feature rapid recovery times that enable smaller magnetic and passive components to be utilized in electronic designs for increased switching speeds and energy efficiency.

Wide Band Gap

Wide band gap semiconductors are captivating materials with remarkable properties. They’re defined by possessing an energy bandgap much larger than that of standard silicon (Si), making these materials capable of revolutionising many electronic and optoelectronic applications.

Silicon carbide is an innovative compound composed of carbon and silicon atoms bonded together in an advanced chemical structure to offer many advantages to electronic circuit design. These advantages include its wide and stable power band gap which enables diodes to withstand higher voltages and currents than traditional P-N silicon-based devices, plus an efficient thermal conductivity for effective cooling.

SiC diodes offer superior power switching performance when it comes to switching applications due to their quicker recovery time. This makes them ideal for high-speed, high-power systems where high performance is desired while at the same time energy losses are reduced, improving system efficiency levels and decreasing total dissipation levels.

A silicon carbide diode uses a Schottky barrier structure, consisting of metal contacts – usually platinum (Pt) or titanium (Ti) – and thin layers of n-type SiC semiconductor material connected with an internal current passing through only in one direction. Under forward bias, these metal contacts act as Schottky junctions to allow current to flow only one direction through them.

Under reverse bias, SiC diodes experience a discharge of their internal self-capacitance across the Schottky barrier that results in an abrupt drop in voltage at their metal-semiconductor interface and then leads to an increase in electric field, potentially breaking down their barrier and leading to device breakdown.

Nexperia, an expert in essential semiconductors, recently entered the high-voltage wide bandgap market with its new industrial grade SiC Schottky diodes with an operating voltage range between 650V and 10A. These diodes can be used in power supplies or rectifier circuits to convert high voltage power sources, including surface mount (DPAK R2P and D2PAK R2P) or through hole (TO-220-2, TO-247-2) packages; engineering samples are now also available for request.

High Thermal Conductivity

Wide bandgap semiconductors such as SiC are renowned for their superior thermal conductivity compared to conventional silicon diodes, enabling the device to dissipate heat more effectively, leading to higher power densities within one package and accommodating additional components within limited spaces. This feature can prove particularly advantageous in power converter applications where efficiency is key as well as systems which experience transient thermal events which could otherwise damage or destroy its device.

Silicon Carbide Diodes feature improved thermal performance that also increases their margin against overvoltage stresses, providing more room to handle larger surge currents and complex driving requirements without sacrificing performance or reliability. This extra margin can prove especially valuable in applications like photovoltaic solar systems and electric vehicle (EV) charging where environmental conditions may be difficult.

SiC diodes boast high thermal conductivity, which allows them to withstand much higher operating temperatures than their silicon counterparts while still dissipating enough heat to protect the circuitry from overheating. This allows them to function in more demanding environments while helping designers reach greater energy efficiencies while decreasing system cost, weight and footprint.

Metal Schottky junctions allow only electrons to pass across, unlike in standard PN junctions where holes and electrons flow simultaneously. This allows this type of power device to turn on and off faster than traditional silicon diodes while having lower reverse breakdown voltages.

Silicon Carbide Diodes have an inherent drawback when used for more demanding applications; however, their high-reverse breakdown allows designers to overcome this limitation with higher reverse voltage than standard silicon diodes would allow. This higher reverse breakdown voltage enables power devices with increased reverse breakdown to be safely used in more challenging applications without risk of damage or failure, giving rise to systems with greater efficiency and lower total cost than could otherwise be accomplished with conventional silicon devices.

High Current Capacity

Silicon carbide diodes offer superior current capacities compared to their silicon counterparts, which allows them to be utilized in applications requiring fast switching speeds such as power supplies and uninterruptible power supplies. Their higher current capability also helps improve efficiency while simultaneously decreasing component size and cost.

Silicon carbide diodes have an increased current capacity due to their lower forward voltage drop and faster recovery time, which allows for quicker switching times while reducing power losses within power supplies. Furthermore, this reduced power loss also allows higher operating temperatures to improve reliability of these devices.

Silicon carbide diodes boast superior thermal conductivity compared to their silicon counterparts, enabling more effective heat dissipation, leading to reduced resistance and an increase in current density. When combined with their low forward voltage drop and fast recovery time, a silicon carbide Schottky diode creates an outstanding high-performance device suitable for many different electronic applications.

Silicon carbide Schottky diodes offer several distinct advantages over standard diodes. One such advantage is their ability to withstand large surge currents due to the structure and natural durability of silicon carbide semiconductor material, making this type of diode ideal for use in high-performance applications like industrial motor drives, solar inverters and electrical vehicle circuits.

Wolfspeed provides a selection of silicon carbide diodes, such as the 650 V Silicon Carbide MPS (Merged PiN) Schottky diode with low forward voltage drop and excellent surge current handling capabilities. This diode can be found in high performance power electronics applications like industrial motor drives, energy storage systems and solar inverters as well as providing excellent results when used as servo drives or compressors for heating pumps and air conditioners.

Fast Recovery

SiC diodes offer numerous advantages over their silicon counterparts. Thanks to its wide band gap, high current capacity, and increased thermal conductivity properties, SiC devices enable power electronics systems to function at higher temperatures, voltages and speeds than ever before.

SiC Schottky barrier diodes boast shorter reverse recovery times than silicon (Si) diodes, enabling them to turn on at lower voltages while handling higher currents without sacrificing reliability. They also have lower forward voltage drops than Si diodes allowing for faster switching on and off speeds and reduced power losses.

SiC diodes exhibit swift reverse recovery due to their absence of depletion regions; as a result, during reverse bias no minority carriers (holes) exist in the n layer, only electrons flow across the junction, and recovery occurs much more rapidly compared to conventional PN diodes.

As the pioneering SiC discrete power supplier in the world, Infineon recognizes that reliability is of utmost importance. To meet this goal, they have implemented comprehensive quality and reliability control programs which ensure all their SiC diodes meet stringent quality specifications.

Infineon’s SiC SBDs undergo rigorous static parameters testing and surge current handling testing to ensure optimal performance, and rigorous avalanche capability tests to ensure they can safely be used in high-voltage applications.

SiC SBDs from Infineon boast long lifespan and high switching frequency, making them suitable for an array of power electronics applications in automotive, aerospace and defense, renewable energy, industrial and consumer electronics markets. Furthermore, SiC SBDs have smaller sizes and higher breakdown voltages than traditional silicon diodes – ideal for use at higher temperatures in demanding applications – while also being environmentally-friendly alternatives to silicon-based semiconductors which may become harmful if released into the environment.