In speed, temperature and power handling, gallium nitride is set to take over as silicon power devices reach their limits. GaN is the technology that will allow us to implement essential future cleantech innovations where efficiency is a key requirement.
The excitement about GaN stems from its unique material and electronic properties. GaN devices offer five key characteristics: high dielectric strength, high operating temperature, high current density, high speed switching and low on-resistance. These characteristics are due to the properties of GaN, which, compared to silicon, offers ten times higher electrical breakdown characteristics, three times the bandgap, and exceptional carrier mobility.
Taking advantage of these properties GaN Systems has successfully developed transistors with an on-resistance lower than attainable with silicon, and even better than a mechanical relay contact. This together with GaNs inherent negligible charge storage, in turn permits the design of power switching circuits with formerly unheard of efficiencies, small size and very low heat losses. Using a unique proprietary custom island topology the company has enabled the designs to be transfered easily from silicon carbide based wafers to lower cost silicon wafers.
Technical advantages
Silicon (Si) technology displaced almost all the earlier low power thermionic and electromechanical devices, but fundamental material limitations have stalled its use in higher power applications. All power electronic systems of the future will take full advantage of wide bandgap devices such as GaN. The advantages include;
Reduced heat sink requirements
80% reduction in system volume and weight
Lower voltage drop for unipolar devices
Increased output power
Improved transient characteristics and switching speed
Reduced electrical noise from smaller system packages
Reduced electrical noise due to virtually zero recovery charge
Learn About GaN
GaN System's Girvan Patterson discusses what GaN FETs can do for the design of automotive inverters. In one case, a GaN-based 12-kW inverter took the place of a silicon version weighing 70% more and occupying 80% more space. The device goes in mild hybrid vehicles and was designed by an automotive OEM.
This video covers a few details about the winner of Google's LiTTLE BOX challenge to create an inverter with 50 W/in.-cubed power density. The winner, CE&T in Belguim, used GaN Systems parts to create an inverter having 143 W/in.-cubed.
Introducing the family
GaN Systems' complete family of GaN-on-Si power switches
Applications
GaN Systems develops and manufactures gallium nitride transistors targeted at efficient power conversion for solar, wind and smart-grid, electric and hybrid vehicles, and high efficiency power supply applications.
Switch mode power supplies (SMPS)
UPS & motor control
Cleantech – solar, wind & smartgrid
Hybrid and EV battery control & health management systems
Power factor correction controllers (PFC)
Hybrid and electric vehicles have a substantial power conversion requirement – a typical drivetrain can be switching 100kW. A typical silicon-based converter will be optimally 95% efficient – therefore having a 5% loss – or 5kW. These losses, as heat, have to be disposed of, and the current solutions involve water-cooling and separate radiator systems. GaN converters can achieve 98 to 99% efficiency – a threefold reduction in losses, and thanks to GaNs higher operating temperatures, can be air-cooled. Of equal importance the silicon efficiency of 95% is only achieved at optimum full load; at low load the efficiency drops to the order of 70%. Due to the smaller drive circuit losses, GaN Systems devices can maintain efficiencies higher than 90% even at low loads.
Whenever power has to flow from its source to destination some form of control system is necessary. As new sources of energy are explored – wind, tides, bio-fuels – the need increasingly arises for ever more efficient controlling systems to link the power into our power grids for distribution to the user. GaN, with its higher power and temperature capabilities, and hence efficiency, creates the next generation of power control systems that will make these new sources viable.
Products
Gan Systems offers an industry leading selection of power transistors.
Cool Switching – that summarizes the benefits of our unique island based topology and products – highly efficient low loss transistors and integrated systems.