SiGe power transistor operates to 5 GHz

 RQG2003 is a high-performance power SiGe HBT intended for operation at 2.4 GHz and 5 GHz. In IEEE 802.11 a/b/g wireless LAN routers/terminals, RF tag readers/writers, digital cordless phones, and similar products, this power transistor can eliminate the power amplifier modules and monolithic microwave integrated circuits (MMICs) typically used to drive the transmitting antenna. As a result, it allows engineers to design systems that consume less power, are smaller, and cost less to build.

At 5.8 GHz, for example, the SiGe device has a power gain of 6.4 dB, a 1 dB gain compression power of 26.5 dBm, and a power addition efficiency of 33.6%. At 2.4 GHz, it provides a power gain of 13.0 dB, a 1 dB gain compression power of 26.5 dBm, and a power addition efficiency of 66%.

The RQG2003 is the first Renesas Technology product to use the double-trench structure, in which trench isolation and a conductive trench are formed in a single transistor area. This structure reduces the parasitic capacitance between the substrate and transistor that degrades high-frequency characteristics, resulting in a major improvement in power gain and power addition efficiency in the 2.4 GHz and 5 GHz bands. Also, the conductive trench is constructed in a way that connects the electrodes and substrate by means of via holes, making it possible to reduce the inductance originating from wire bonding, for improvement in power gain and power addition efficiency.

The RF power transistor is built with a SiGeC process, in which a SiGe base is doped with carbon, and has an optimized transistor pattern. These techniques have increased the collector current density and improved the 1 dB gain compression power by approximately 1.5 dBm compared with the HSG2002 device. The RQG2003 uses an optimal silver paste to achieve high reliability and conductivity for die bonding. A Sn-Bi (stannum-bismuth) compound is used for package electrode plating, providing a totally lead-free implementation.

The RQG2003 is available in the 8-pin WQFN0202 package. The device will be available in March, with a sample price of $0.87 each.

Texas Instruments has introduced several battery management integrated circuits (ICs) including its next-generation Impedance Track "gas gauge" chipset. They enable improving battery performance and protecting multicell, lithium-based battery packs used in notebook computers and other systems.
One example is TI's bq20z90 Impedance Track battery gas gauge that monitors battery capacity, impedance, cell balance, open-circuit voltage and other critical parameters of a 7.2 V, 10.8 V or 14.4 V battery pack and reports the information to the system host controller over a serial-communication bus.

TI's Impedance Track gas gauge technology, launched in 2004 with the bq20z80 chipset, precisely measures changes in impedance, or resistance caused by battery age, temperature and cycle life, to accurately predict run-time of battery packs with two, three and four cells in series. An exact "starting position" is determined for instant state-of-charge. Then total capacity is calculated from the amount of capacity that exists, which eliminates the need for a full-charge and discharge cycle.

The bq20z90 drives a three-, four- or five-segment LED display for remaining capacity indication. The device integrates SHA-1, 128-bit decryption functionality which easily identifies potentially unsafe batteries not approved by original equipment manufacturers for use in their devices. If the battery information checks out, the system will allow normal system operation with the battery pack. A manufacturer can program the system to take action to protect the consumer if the battery pack response is not correct, or if the battery pack is not approved or determined to be defective.
The bq20z90 is available in volume production from TI and its authorized distributors. The device is packaged in a 30-pin thin shrink small outline Package (TSSOP). The suggested price in 1000 piece quantities is $3.30.