Engineers attending the Power Electronics Technology Conference and Exhibition, which runs through Thursday of this week at the Long Beach Convention Center, are getting a glimpse of the latest power semiconductor developments as vendors such as Infineon Technologies, ST Microelectronics, Cree, and International Rectifier, unveil their newest MOSFETs and IGBTs.
Infineon Technologies (www.infineon.com) is using the event to introduce its OptiMOS 3 family of 30-V n-channel MOSFETs. These MOSFETs promise to improve power supply reliability, while boosting energy efficiency by 1% to 1.3% over that of previous generation MOSFETs in the target dc-dc applications. The company claims best-in-class on-resistance for these MOSFETs as well as low gate charge. For example, an OptiMOS 3 power MOSFET in the company’s SuperSO8 package has a max RDS(ON) of 1.6 mΩ. In addition, the company will offer the devices in a new high-performance Shrink SuperSO8, which measures 3 mm x 3 mm.
Infineon is also introducing its fourth-generation CoolMOS CP family of devices with 500-V ratings. This family includes a device with a figure-of-merit of just 6.7 ΩnC in a TO-220 package. RDS(ON) for this device is 140 mΩ.
Meanwhile International Rectifier (IR) (www.irf.com) is extended its portfolio of parts in the DirectFET package to include a 200-V HEXFET MOSFET designed for use in isolated dc-dc converters operating from the industry standard 36-V to 75-V range. Up until now, DirectFETs were only available in ratings up to 100 V. But with the introduction of the IRF6641TRPBF, IR’s unique package with the double-sided cooling can be used in applications such as motor drives, class D audio amplifiers, and instrumentation.
In addition, designers of the isolated dc-dc converters can now use DirectFETs on the primary side of their converters. According to IR, one of the benefits of the new device is that it can reduce primary-side FET temperatures by up to 13˚C and reduce overall solution size by up to 50% versus two or three SO-8 devices. The IRF6641TRPBF specifies an RDS(ON) of 59.9 mΩ max at 10 V and a QG typical of 34 nC.
Cree (www.cree.com) is unveiling a part that copackages a silicon IGBT with a silicon carbide schottky to reduce the transistor’s switching losses. The n-channel transistor and the schottky are housed in a TO-220, and specify ratings of 600 V for VCES, 15 A for IC, and a 10 µs short-circuit capability. In addition, VCE(ON) is typically 1.8 V.
STMicroelectronics (www.stm.com) announces that its STBST01 ESBT base driver, originally made for a single customer, is now openly available in production quantities. The STBST01 is designed to simplify driving of the emitter-switched bipolar transistor (ESBT) by providing the bias to the bipolar transistor through a discrete PNP pass element. The bias determines the tail current duration of the ESBT, which is programmed by the value of a resistor tied between ground and the programming pin.
The ESBT is essentially a bipolar NPN transistor stacked on an NMOS transistor. This device has efficiency and speed advantages of conventional MOSFETs, as well as the robustness of a bipolar device. However, it also has separate inputs for the NMOS and bipolar transistors, making the device slightly more complicated to drive.
According to ST’s Luca Difalco, Business Manager for New Products and Market Development, the STBST01 controls the recovery time of the bipolar transistor by carefully measuring the delay between the NMOS gate turn off and the voltage rise on the collector of the bipolar transistor. The bias is increased or decreased to provide the desired recovery time.
In addition, to the above developments, some interesting non-semiconductor developments are being unveiled in Power Electronics Technology Exhibition. One of the more interesting ones comes from connector developer Tribotek (www.tribotek.com).
Using its LowR contact system, Tribotek has developed a high-current socket for bus bar-based power distribution. The BusBlade connector provides 400 A to 600 A of capacity on a single bus bar-to-bus bar connection using a blade that is approximately 1.250 in.wide. The socket is designed to replace existing sockets that only handle 250 A of current.