Ceramic Varistor Offers Advanced Performance in Small Footprint
A manufacturer of advanced passive components and interconnect solutions has expanded its zinc oxide (ZnO) varistor series to include an 18-V version with a maximum 1-µA leakage current. The UltraGuard Series multilayer ceramic varistors from AVX Ltd extend battery life in portable devices.
The varistors feature nonlinear, bi-directional voltage-current characteristics similar to back-to-back zener diodes with an electromagnetic compatible–capacitor in parallel. The series offers several electrical advantages over zener diodes, according to the manufacturer. These include better repetitive strike and inrush current capabilities, faster turn-on time and inherent EMI/RFI attenuation. The enhanced performance has been achieved in a significantly smaller footprint to save important board space.
The robust UltraGuard Series also features multistrike capabilities and will survive 1000 strikes at 15-kV contact ESD.
Designed for applications where low power consumption is a primary concern, the multilayer ceramic varistor is suited for transient protection applications where extended battery life is required.
The ceramic varistors come in discrete chips in 0402, 0603, and 0805 sizes; two-element packages in 0405 and 0508 sizes; and four-element 0612 packages. Low- and high-capacitance versions are offered.
AVX Ltd
Fleet, UK +44 1252 770 000
www.avx.com [5]
Medical imaging T/R switch
Described as an industry first, an integrated, eight-channel transmit/receive (T/R) switch for ultrasound systems has been introduced by Texas Instruments (TI). The TX810 will enable designers to meet demand for smaller portable ultrasound systems while speeding time to market, says the company. The component integrates a protection diode bridge and clamp diodes for each of its eight channels. This design prevents the high-voltage pulses of the transmitter from damaging the receive electronics of the ultrasound system. The device saves more than 50% board space, compared with discrete solutions, in portable to mid-range ultrasound systems. The reduction in size and easier handling also improve reliability, according to the company. The TX810 comes in a 36-pin 6-×-6-mm QFN package. Full production of the components was scheduled to begin in December 2009. The product completes TI’s signal chain offering for ultrasound systems together with the AFE58xx family of analogue front ends, the TX734 high-voltage pulser and a portfolio of embedded processors.
Texas Instruments
Freising, Germany +49 8161 802 121
www.ti.com [6]
Load cells
Off-center load cells that reduce errors caused by force misaligments are available from DS Europe. They are suited for applications in which forces and weights that need to be measured are susceptible to misalignment along a load cell’s measuring axis. The cells also transmit data to a PLC or computer without electrical noise and in high resolution. The 500QD load cells are available with optional built-in analogue (±5 or ±10 V and 4–20 mA outputs) or digital (CAN open, RS 485 and RS 422 outputs) electronics. The electronic systems are mechanically protected and shielded, thus avoiding the need for external electronic components. The built-in analogue parts are precalibrated by the manufacturer and feature an amplified signal with zero and gain settings and a good signal-to-noise ratio. The advantages of digital electronic systems include data transmission that is immune to electrical noise, and high resolution and sampling rates.
DS Europe Srl
Milan, Italy +39 0 2891 0142
www.dseurope.com [7]
Blue LEDs
High-output blue light-emitting diodes that have a narrow beam angle are suited for fluorescence in medical, scientific and forensic applications. The new OD-469L LEDs from Opto Diode Corp. are available in a hermetically-sealed TO-5 can with three leads. At 25°C, the LEDs deliver total power output ranging from a minimum 80 to 170 mW. The dominant emission wavelength is from 465 to 475 nm with typical operation at 470 nm. Absolute maximum ratings (at 25°C) include 1000-mW power dissipation (infinite heatsink), 350-mA continuous forward current, peak forward current at 2 A, and reverse voltage at 5 V. Thermal parameters for storage and operating temperature are -55° to 100°C, with the maximum junction temperature at 125°C. The lead soldering temperature (at 1⁄16 in. from the case for 10 seconds) is 260°C, making the LEDs easy and convenient to install into existing or new system designs.
Opto Diode Corp.
Newbury Park, CA, USA +1 805 499 0335
www.optodiode.com [8]
Image-processing board
An image-processing platform from 4DSP provides two high-speed video streams for real time JPEG2000 compression. Powered by dual Altera Cyclone III FPGA image processors and two analogue hardware devices, the VID375 video image processor is designed to provide image compression that meets the needs of precise medical-imaging and other industrial applications. The board features a dual JPEG2000 hardware compression engine based on the dual ADV212 CODEC devices. The VID375 is suitable for on-the-fly compression prior to or after imaging processing. Low-cost dual Altera Cyclone III devices are closely coupled to fast on-board DRAM memory resources to provide efficient hardware compression available for the embedded image signal processing market. With the flexibility of the architecture and the use of an industry standard Camera-Link interface, the VID375 makes possible the lossless compression and high-speed storage of video. The VID375 produces a JPEG2000 wavelet-based digital compressed image, superseding the discrete cosine transform-based JPEG compression method. Up to 140 megapixels per second from two independent cameras can be compressed on the fly from a single VID375 board. It can either encode the video frames prior to or after applying an advanced video and imaging algorithm.
4DSP bv
Alphen aan den Rijn, Netherlands +31 17 278 2190
www.4dsp.com [9]
Dc-ac inverter
A 150 × 50 × 10-mm dc-to-ac inverter for driving up to four cold-cathode fluorescent lamps (CCFLs) in liquid-crystal display (LCD) backlighting applications is designed for use with 305- to 432-mm industrial-grade LCD panels. The compact, low-profile LS6Q-1612A-RH from Taiyo Yuden provides dual LCD panel capability. It features brightness and backlight on–off control and a 5-V alarm output for signalling when the inverter detects a CCFL open condition. Suitable for medical electronic, touch screen and test and measurement equipment applications, the RoHS-compliant device provides an input of 12 V dc and output current of 3.3 to 6 mA rms for each lamp. Its CCFL-driving circuit includes a self-oscillating dc-to-ac convertor that minimises electromagnetic interference. Device output power is 4 W per lamp.
Taiyo Yuden Europe GmbH
Fürth, Germany +49 9119 3640
www.taiyo-yuden.com [10]