046-047_EETE-VF

EETE SEPTEMBER 2012

DESIGN & PRODUCTS Reader Ultra-low IR Schottky barrier diodes prevent Five Wi-Fi radio transceiver thermal runaway at high temperatures development kits to win The RBxx8 series of ultra-low reverse current Schottky barrier diodes from Rohm Semiconductor are capable of operating The RTX4100 Wi-Fi module from RTX is at high temperatures for use in automotive and power supply a single stream, 802.11 b/g/n Wi-Fi module with on-board devices. Power consumption low power application processor. This month, RTX is giving is said to be reduced by ap- away 5 RTX4100 Wi-Fi development kits worth USD 399 proximately 40% compared each for EETimes Europe’s readers to win. Designed for the to conventional automotive easy application development of a wide range of machine- rectifier diodes, making these to-machine applications, devices suitable for energy- the 30x18x2.4mm radio saving circuits in electric module features two vehicles (EVs) and hybrid push buttons and a dual electric vehicles (HEVs). colour LED (red/green) Rectifier and fast recovery for the application user diodes (FRDs) are commonly used in circuits for automotive interface. External sen- and power supplies exposed to high temperature environments sor solder-points enable due their strength against thermal runaway. However, they often users to connect digital feature high VF, making it difficult to reduce power consump- or analogue sensors. The RTX4100 module also integrates tion to the levels required for EVs and HEVs. As a result, there a 3-axis accelerometer and compass and a 28-pin expan- has been an increasing demand for low- VF (Forward Voltage) sion/debug connector. It draws as little as 4uA in low energy Schottky barrier diodes that can support operation at high tem- mode. The RTX4100 DVK (development kit) offers a com- peratures. Rohm has used high temperature-resistant metals to prehensive way of evaluating the performance and features achieve what the company believes to be the industry’s lowest of this Wi-Fi module as well as developing custom code. It reverse current – approximately 100 times smaller than that of includes an evaluation kit (EVK) with ready to use hardware conventional SBDs, ensuring compatibility with high tempera- and software, including the RTX4100 Wi-Fi module mounted ture environments. on a small carrier board with integrated sensors. The pack- ROHM Semiconductor age comes complete with a USB-UART cable with adaptor, www.rohm.com/eu a 3-cell battery holder and AAA batteries, a docking station for the Wi-Fi module, the source code of various demo ap- Micro disc piezoelectric gas pump delivers in plications and documentation. excess of 600 mbar, silently Check the reader offer online at Cambridge-based TTP has invented a miniature gas pump that replaces traditional mechanical operation with ultra- www.electronics-eetimes.com sonic pressure generation technology and runs silently. The patented micro Disc Pump has already been com- 6-bit serial-controlled digital step attenuators mercialised in a wound therapy application and is offer high accuracy in 0.5dB steps well suited to other portable RFMD’s new RFSA2644/2654 6-bit digital step attenuators medical applications such (DSAs) feature high linearity over their entire 31.5dB gain control as blood pressure mea- range with excellent step accuracy in 0.5dB steps. They are surement, as well as micro-fluidic and industrial applications programmed via a serial mode where size, noise and controllability are important design control interface that is both 3V and factors. The device uses a piezoelectric actuator to drive 5V compatible. They also offer a pressure oscillations in a thin disc shaped cavity: one current rugged Class 1C HBM ESD rating model measures just 4mm in thickness. Silent operation via on-chip ESD circuitry. The MCM is achieved by running the pump at frequencies above the package is footprint-compatible limit of hearing, using special custom, high-speed valves to with most 24-pin, 4x4mm QFN rectify the pressure oscillations. The combination of pressure packages. The RFSA2644 operates generation technology and high frequency operation make in the 50MHz to 4000MHz fre- it possible to deliver pneumatic performance significantly quency range whilst the RFSA2654 higher than traditional pumps of comparable size, claims the is for use in the 5MHz to 2000MHz manufacturer. With a wide dynamic range, the TTP technol- range, with an attenuation range of ogy has already achieved stall pressures in excess of 600 31.5dB in 0.5dB steps and a step mbar and flow rates of more than 2,500 cc/mn. The high- accuracy of +/- 0.1dB. The chips frequency piezoelectric mechanism provides virtually ripple- can be used in transceiver RF and free output compared to the pulsed output that characterises IF applications including 2G, 3G, most conventional pumps. LTE, WiMax/WiFi and other wireless TTP Group data terminals. www.ttp.com RFMD www.rfmd.com 46 Electronic Engineering Times Europe September 2012 www.electronics-eetimes.com


EETE SEPTEMBER 2012
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