Nearly half of the world’s total power demand comes from motors, and with the continued spread of electrical appliances in emerging and developing countries, this percentage is expected to only increase. IGBTs are commonly used as switching elements in inverters that drive motors in home appliances such as refrigerators and aircon but the demand for improved energy efficiency is driving the increasing use of MOSFETs with higher switching speed and lower conduction loss in the relatively low current condition.
The R60xxJNx PrestoMOS power MOSFETs have the industry’s fastest reverse recovery characteristics, achieving lower power consumption and a proprietary lifetime control technology to achieve ultra-fast trr. This enables a reduction in power loss of about 58% at light loads when compared with IGBT implementations. Raising the reference voltage needed to turn ON the MOSFET prevents self turn-ON, which is one of the main causes of loss, while optimising the characteristics of the built-in diode allows for a soft recovery index specific to super junction MOSFETs, which reduces noise that can lead to malfunctions. Eliminating these barriers to circuit optimization provides customers with greater design flexibility.
Switching speed increase, self turn-ON, and noise generation are conflicting phenomena, making it necessary for customers to optimize circuitry by adjusting the gate resistance and other factors during circuit design. Unlike general-purpose MOSFETs, Rohm’s R60xxJNx series takes measures against noise and self turn-ON, providing engineers with more design freedom. Optimising the parasitic capacitance inherent within the MOSFET structure reduces unintended gate voltage during switching by 20%.
Generally, the recovery characteristics of the super junction MOSFET’s internal diode shows hard recovery. However, by optimizing the internal structure, the R60xxJNx series is able to improve the soft recovery index by 30% over conventional products and succeed in reducing noise while maintaining the industry’s fastest reverse recovery time (trr). This makes it easy for engineers to adjust the noise from the gate resistance.