Replace silicon IGBTs with SiC MOSFETs, urges Microchip
High efficiency, high reliability 1700V silicon carbide (SiC) MOSFET dies, discrete and power modules have been introduced by Microchip. The SiC devices target energy-efficient electric charging systems powering commercial vehicle propulsion, auxiliary power systems, solar inverters, solid state transformers and other transportation and industrial applications which rely on high voltage switching power devices.
The SiC devices allow engineers to use two-level topologies and reduce part count, while increasing efficiency, says Microchip. They also provide simpler control schemes that are possible with IGBTs because without switching limitations, power conversion units can be significantly reduced in size and weight. The space this frees up can allow room for more charging stations, additional room for paying passengers and cargo, or extend the range and operating time of heavy vehicles, electric buses and other battery-powered commercial vehicles. This is all achievable at reduced overall system cost, adds Microchip.
The SiC devices have gate oxide stability – Microchip observed no shift in threshold voltage even after an extended 100,000 pulses in repetitive unclamped inductive switching (R-UIS) tests. The R-UIS tests also showed “excellent” avalanche ruggedness and parametric stability and with gate oxide stability, demonstrated reliable operation over the life of the system, reports Microchip.
The degradation-free body diode can eliminate the need to use an external diode with the silicon carbide MOSFET. A short circuit withstand capability which is comparable to IGBTs survives harmful electrical transients and a flatter RDS(on) curve over junction temperature from 0 to 175 degrees C enables the power system to operate at greater stability than other silicon carbide MOSFETs that exhibit more sensitivity to temperature, says Microchip.
Microchip also offers AgileSwitch digital programmable gate drivers and a range of discrete and power module packaging, available in standard and customisable formats to speed SiC development.
Other SiC products include families of MOSFETs and Schottky Barrier diodes at 700V and 1200V, available in bare die and a variety of discrete and power module packages. Microchip unifies in-house SiC die production with low inductance power packaging and digital programmable gate drivers.
SiC Spice simulation models compatible with Microchip’s MPLAB Mindi analogue simulator provide system developers with resources to simulate switching characteristics before committing to hardware design. The Intelligent Configuration Tool (ICT) enables designers to model efficient SiC gate driver settings for Microchip’s AgileSwitch family of digital programmable gate drivers.