SemiSouth Announces New 1700V/1400mOhm SiC JFETs Which Simplify Fast Start-up of 3-Phase Power Supplies

Fast start-up, reduced component count, simplified design

SemiSouth Laboratories, Inc., the leading manufacturer of silicon carbide (SiC) transistor technology for high-power, high-efficiency, harsh-environment power management and conversion applications, has announced a new 1700V/1400mOhm silicon carbide JFET which simplifies start up circuit design in 3-phase auxiliary power supplies.

Traditional solutions either use an HV bleed resistor which results in a slow start-up at low line voltages and a high quiescent power loss, or are MOSFET-based which necessitate overload protection and can suffer from high power losses in the MOSFET under fault condition e.g. short circuit. Explains Applications Engineer, Nigel Springett: "By using a depletion mode JFET, designers can achieve a fast start-up using no extra components. Our JFETs need no extra heat sink for this application."

The SJDT170R1400 will come in a newly developed SMD D2PAK-7L package in order to simplify PCB layout and optimize switching performance due to lower inductance. This package will have a high creepage distance of 6.85mm in order to support 1700V applications and is sized of 16x10x4.4mm.

"We are confident that the SJDT170R1400 will become the de-facto standard for all auxiliary 3phase power supplies, as the benefits for the users are superior compared to traditional High Voltage MOSFET solutions and the cost become less for the total solution", says Sr. Vice President Sales & Marketing, Dieter Liesabeths.

SemiSouth is initially sampling the normally on 1700V/1400mOhm SJDP170R1400 in TO-247-3L packaging; the SJDT170R1400 in surface mount D2PAK-7L high creepage package will sample in Q3/2012.

About SemiSouth Laboratories, Inc.

SemiSouth, a privately owned corporation with its main offices and foundry in Starkville, Mississippi, (USA), focuses on silicon carbide (SiC) power devices and electronics, targeting applications such as: solar inverters; power conversion in computing and network power supplies; variable-speed drives for industrial motors and hybrid electric vehicles; and products used in high-power, harsh-environment military and aerospace environments. The company was formed in 2000, has sold products globally through direct sales or distributors since 2005, and received a major growth investment from Power Integrations (NASDAQ: POWI) in 2010. It introduced the world's first commercial, cost-effective normally-off SiC JFETs in 2008, which have enabled world-record energy efficiencies for its customer's products. More information is available at

For further information:

Brenda Temple

Director of Inside Sales and Contracts

SemiSouth Laboratories, Inc.

Tel: +1 (662) 324 7607 ext. 29


For press enquiries:

Nick Foot, PR Director

Billings Group

Tel.: +44-1491-636 393


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