Schottky Diodes
An integral part of the power electronics world, Schottky diodes are everywhere because they are efficient and fast-switching. Combined with Silicon Carbide they offer even more benefit to be the component of choice for high-performance applications; electric vehicles (EVs), and of course power inverters and other industrial power systems. We take a brief look at the workings of the Silicon Carbide Schottky Diode (SiC SBD), and the advantage it brings over the more common silicon diode.
A Schottky diode is a low barrier current conduction device formed by a metal-semiconductor junction as compared to the compound semiconductor junctions of standard devices. This lower barrier reduces the drop needed for conduction to about 0.2 to 0.4 volts, as against the 0.7 volts of most silicon types. Schottkys have a lower capacitance than all but the most exotic of the standard semiconductor diode types, allowing them to switch faster, and the reduced drop means that less power is dissipated so that the efficiency from that reason is higher.
So why do we really want Silicon carbide?
“Silicon carbide (SiC) diodes, are of enormous and growing interest to the power system designer. The SiC family is a new family of components and diodes based upon this material offer enhanced performance. What properties does this silicon carbide inherit from the parent material? Compared to silicon he says that silicon carbide has greater voltage capability, much higher temperature capability, much improved thermal and better conductivity, signalling capability can be higher switching frequencies, is harder”.Faster Switching: As SiC diodes can be switched faster, less “switching up/down losses occur, and so begin to increase the overall efficiency of the power circuits.
How Does it Work?
SiC Schottky diodes basically work very much the same way as standard Schottky diodes, except the added advantages of silicon carbide. They are a metal-semiconductor junction device (the metal either palladium or platinum) using the silicon carbide as the semiconductor. Forward biased and the current can flow across the metal semiconductor junction with little problem, and so the very low forward voltage drop, and the much greater speed of switching of SiC, make these excessively usefully where efficiency and speed of response are desirable.
Main Characteristics:
Low Forward Voltage Drop: The Schottky of SiC has a far lower forward voltage than a silicon so much less power is wasted in the process.
High Reverse Voltage Capacity: Using a high reverse voltage and the SiC Schottky devices are unserviceable without breaking down, so that these very advantageous diodes can be put toFast Switching: This means that the SiC has a fast switching period which effectively reduces switching losses in power conversion.
Use of the SiC Schottky diode
The advantages that these useful diodes in the form of SiC have mean that they are used in many types of application including:
Power inverters.SiC Schottky diodes can be used on power inverters where the rapid switching and ability to accept a high voltage means a more efficient power conversion and less energy wasted.
Applications of SiC diodes
Electric Vehicles (EVs): Critical to the greater efficiency of the powertrain in the EV, the SiC diode means a better use drawing from the battery and transferring to the motors, make longer range and longer life possible.
Renewable Energy: Used in photovoltaic systems where the DC to AC power conversion process, the lower forward voltage drop in power converters can lessen losses and optimise efficiency of the PV plants.
Industrial Power systems: Used in industrial applications where it is possible to have very rapid switching, high voltages, at high temperatures! Applications such as motor drives, UPSs, and high-voltage circuits.
Advantages over conventional Silicon diodes
Greater Efficiency: A faster buck means that the devices can cope with a lower forward voltage drop, and other losses are less, meaning that the overall conversion from one voltage to another is more efficient.
Better reliability: These diodes, being better able to work at high temperatures and with high voltages means that they will be more durable and thus the choice of diodes in e.g. automotive, industrial, and energy applications.
Smaller size: The reduced losses, and greater efficiency of the devices means that the overall circuit design can be a smaller one helping, in an aim to not make your power electronics that bit smaller.
Cost Saving: While it is true that the SiC diodes will be more expensive in the first place, the better efficiencies, and longer life it will produce a cost saving over time from both lesser energy used and better reliability meaning less maintenance.
Summary
Silicon Carbide Schottky Diodes(SiC) are an exciting new direction in power electronics, being able to work at a higher voltage, with higher temperatures, at higher frequencies, while having lower losses. More and more applications are coming into use from electric vehicles, power inverters, and renewable energies. Win the edge for your company with some consideration to cutting better profits, and greater reliability with the SiC Schottky diodes in your systems, they can improve performance and reduce costs of your system, save money and be that very little bit more efficient making the greatest trend of them all, a sustainable, and sustainable.