Toshiba America Electronic Components Inc. (TAEC, Irvine, CA) announced a new family of bipolar power transistors for portable electronics devices. Developed by Toshiba Corp. (Irvine, CA), the transistors can lower power requirements and extend the battery life of portable devices. Typical circuit applications for the new transistors in portable electronics include load switches for power management, inverters, dc/dc converters, charging circuits for built-in rechargeable batteries, series regulators, cellular phones, digital still cameras, video cameras, personal digital assistants, portable audio players and notebook PCs.
The new transistor family is based on Toshiba's third-generation, high-efficiency, mesh emitter transistor (Hi-MET III) design. Compared to conventional bipolar transistors, the Hi-MET III transistors exhibit saturation voltage characteristics between the collector and the emitter, and dc current gain characteristics. The resulting power efficiency enables the manufacture of portable devices with lower power requirements and longer battery lifetimes. As an example, the 2SC5755 transistor features a maximum saturation voltage of 0.12V, with high current gain from 400 to 1,000.
The new power transistors are packaged in three types of small surface-mount packages to meet various design requirements. The three-pin TSM package measures 2.8mm x 2.9mm x 0.7mm, the six-pin VS-6 measures 2.8mm x 2.9mm x 0.7mm and the three-pin PW-MINI measures 4.6mm x 2.5mm x 1.6mm. Samples of the new devices are available now, with pricing ranging from $0.07 to $0.08 each. The devices are currently in mass production.
