STMicroelectronics of Geneva, Switzerland has unveiled new automotive-qualified silicon carbide (SiC) diodes for on-board battery chargers (OBCs) in electric vehicles such as plug-in hybrids (PHEVs) that demand high power-handing capability within a confined space.
The diodes allow designers to build smaller power modules, which suits automotive applications and makes also them a strong choice for tackling the Little Box Challenge presented by Google and IEEE. ST is a device-manufacturer partner of this new $1m competition to design kiloWatt-scale inverters that are more than ten times smaller than existing inverters for various applications, particularly solar micro-generators.
The diodes prevent high-current spikes from damaging the device. Until now, designers have typically over-specified the diodes for safety, whereas ST says that its new technology provides 2.5 times greater over-current capability versus rated current. This enables the use of lower-current diodes, which are smaller and more economical, without compromising reliability or losing efficiency, it is claimed.
ST’s new SiC diodes are automotive qualified, and feature increased reverse-breakdown voltage of 650V, satisfying the voltage de-rating factors applied by designers and car manufacturers to ensure suitable safety margin between normal and short-term peak voltages across the semiconductors used in on-board battery chargers.
The devices build on the known energy-efficiency advantages of SiC as a wide-bandgap (WBG) technology that enables lower switching losses and higher voltage ratings in relation to device size, compared to conventional silicon devices. The new 650V devices include the 10A STPSC10H065DY in a TO-220AC power package and the 12A STPSC12H065DY in TO-220AC. In addition, the STPSC20H065CTY in a TO-220AB package and STPSC20H065CWY in TO-247 are 2x10A dual-diode devices that help maximize space utilization and reduce the weight of the on-board battery charger.
All the new devices are in production and ready for immediate delivery, priced from $4.15 each in 100-unit quantities of the STPSC10H065DY.
