New 1700-V/1400-mOhm SiC JFETs simplify fast start-up of 3-phase power supplies

May 16, 2012 // By Paul Buckley
SemiSouth Laboratories, Inc., is unveiling a new 1700 V/1400 mΩ 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 6.85 mm in order to support 1700 V applications and is sized of 16x10x4.4 mm.

“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”, said Sr. Vice President Sales & Marketing, Dieter Liesabeths.

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

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