Replace silicon IGBTs with rugged silicon carbide power devices

29-07-2021 | Microchip Technology | Power

Microchip Technology has expanded its silicon carbide portfolio with a family of high-efficiency, high-reliability 1700V silicon carbide MOSFET die, discrete and power modules.

This 1700V silicon carbide technology is an alternative to silicon IGBTs. The earlier technology needed designers to compromise the performance and use complicated topologies due to restrictions on switching frequency by lossy silicon IGBTs. Also, the size and weight of power electronic systems are bloated by transformers, which can only be diminished in size by increasing switching frequency.

The new product family enables engineers to move beyond IGBTs, alternately using two-level topologies with decreased part count, greater efficiency and simpler control schemes. Without switching limitations, power conversion units can be notably decreased in size and weight, freeing up space for more charging stations, extra room for paying passengers and cargo, or increasing the range and operating time of heavy vehicles, electric buses and other battery-powered commercial vehicles – all at diminished overall system cost.

“System developers in the transportation segment are continuously asked to fit more people and goods into vehicles that cannot be made larger,” said Leon Gross, vice president of Microchip’s discrete product business unit. “One of the best ways to help achieve this is through the enormous reductions in size and weight of power conversion equipment that utilises high-voltage silicon carbide power devices. These same advantages for transportation bring similar benefits to many other industry applications.”

Features include gate oxide stability where the company discerned no shift in threshold voltage even after an extended 100,000 pulses in repetitive unclamped inductive switching (R-UIS) tests. R-UIS tests also revealed excellent avalanche ruggedness and parametric stability and, with gate oxide stability, displayed reliable operation over the system's life.

The degradation-free body diode can eradicate the necessity to employ an external diode with the silicon carbide MOSFET. A short-circuit withstand capability comparable to IGBTs survives harmful electrical transients. A flatter RDS(on) curve over junction temperature from 0C to 175C allows the power system to function at greater stability than other silicon carbide MOSFETs that display more sensitivity to temperature.

The company streamlines the adoption of its technology with a family of AgileSwitch digital programmable gate drivers and a wide range of discrete and power module packaging, offered in standard and customisable formats. These gate drivers help speed silicon carbide development from benchtop to production.

By Natasha Shek