Standalone normally-ON SiC JFET portfolio expanded

The devices are normally-ON with zero voltage gate drive, making them particularly suited for applications such as very fast action, solid-state circuit breakers and circuit protection generally where a default to an ON-state is necessary in the absence of gate power. The devices are also commonly used in series connection with a Si-MOSFET as robust ‘supercascodes’, which give all the advantages of wide band-gap technology with very high operating voltages and easy gate drive. 

Other applications include electronic loads, wireless charging synchronous rectification and power switches in low power flyback converters where the JFET in a cascode configuration provides for easy startup. 

Markets addressed are circuit protection in rail, electric aircraft and traction, along with high voltage switching power conversion.

As devices, SiC JFETs have an extremely good RDSA figure of merit (normalised ON-resistance with die area), giving low insertion loss in circuit protection applications. The parts can be easily parallelled, due to their positive temperature coefficient of RDSON and flat gate threshold voltage curve over temperature. 

When operated in ‘linear’ mode, SiC JFETs exhibit a wide Safe Operating Area (SOA) without current crowding and current filament formation that other technologies suffer from, making them particularly suitable for electronic loads and current limiters. Absence of a gate oxide in the SiC JFETs gives the added benefits of radiation hardness and general robustness.

UnitedSiC uses its proprietary six inch wafer process in the fabrication of the devices with advanced wafer-thinning and die-attach techniques for excellent junction-to-case thermal resistance.

The new Generation 3 devices are coded UJ3N120070K3S (1,200V 70mΩ), UJ3N120035K3S (1,200V 35mΩ), UJ3N0650080K3S (650V 80mΩ) and UJ3N065025K3S (650V 25mΩ). All of these options are available in the convenient TO-247-3L package.

Anup Bhalla, VP Engineering at UnitedSiC, stated: “UnitedSiC’s SiC JFETs offer unbeatable system value when you need normally-ON, super robust devices. The need for circuit protection is growing in tandem with the continuing advancement of power electronics. Very fast acting circuit breakers can simplify power circuitry in rail traction, ships and increasingly electronic aircraft, and SiC JFETs are the simplest, most efficient option for current limiting in these types of applications.” 

UnitedSiC’s Gen-3 SiC JFET prices start at $5.00 in quantities of 1,000 pieces and are available at Mouser and other local distributors.