Semi South Now Shipping High Power SiC JFETs in Commercial QuantitiesFebruary 28, 2011 by Jeff Shepard
SemiSouth Laboratories, Inc. has announced that it is now shipping its latest range of vertical trench JFETs – including the world’s first normally-off family of devices to handle up to 50kW – in commercial volume quantities. The company is rapidly expanding production capacity at its state-of-the-art SiC wafer fabrication facility in Starkville, Mississippi. A completely independent, vertically integrated SiC manufacturer with the most advanced SiC epitaxial and vertical trench process technology in the world, SemiSouth utilizes a proprietary and patented self-aligned JFET chip design enabling up to ten times smaller die size when compared to silicon super-junction MOSFETs or the latest trench IGBTs. The company also holds the record for the lowest 1200V power transistor specific on-resistance - under 2.5mΩ/cm².
The SJEP120R100, SJEP120R063 and SJEP170R550 Normally-OFF trench silicon carbide power JFETs are compatible with standard gate drive circuitry and feature a positive temperature coefficient for ease of paralleling. The voltage-controlled devices also have a low RDS(on)max, low gate charge and low intrinsic capacitance. The SJEP120R100 with an Rds(on) of 100mΩ enables extremely fast switching with no ’tail’ current up to its maximum operating temperature of 175°C, and the SJEP120R063, with an Rds(on) of 63mΩ can enable switching losses of only 353µJ at 24A. These JFETs offer a blocking voltage of 1200V and exhibit temperature-independent switching behaviour. This latter device is being designed in by a number of Solar Inverter companies who are achieving product efficiencies of 98-99%.
SemiSouth also offers a normally-on 1200V SiC JFET (SJEP120R085) for customers who can utilize the normally-on behaviour. It offers the same attractive features as the normally-off SJEP120R100 JFET, and in addition offers a higher saturation current (50A), lower on-resistance per unit area (85mΩ total), and the same or better switching performance. This product is being designed in also at a number of solar inverter and audio customers for high-efficiency or high-linearity applications.
At 1700V, SemiSouth’s new 4A SJEP170R550 SiC JFET delivers a higher blocking voltage (1700V), five times lower on-resistance (550mΩ, around ten times lower output capacitance (COSS = 20pF) and a gate charge (QG of 10nC) than competing 1500V silicon power transistors. It has a maximum operating temperature of 175°C. The SJEP170R550 is targeted for auxiliary flyback power supply applications running off the high voltage dc bus in ac drives, UPS and solar inverters.
Commented Jeff Casady, President, "Our SiC JFETs enable the most energy efficient power system designs now possible for a broad range of applications – and they are available in volume production. Power supplies and inverters can now be designed to run up to 50-75% more efficiently and operate at up to four to eight times higher in PWM frequency. The reasonably higher price of the JFET can be off-set by a substantial reduction in the size and cost of magnetics, heat sinks and enables a smaller and lighter overall solution."
SJEP120R100, SJDP120R085, SJEP120R063 and SJEP170R550 JFETs are available in plastic TO-247 packaging and are priced in 1000 piece quantities at $12.55 for the SJEP120R100, $15.50 for the SJDP120R085, $22.87 for the SJEP120R063 and $9.06 for the SJEP1270R550.