Oct 15 2008
Micrel, Inc., an industry leader in analog, high bandwidth communications and Ethernet IC solutions, today launched the MIC4833/4, a new series of 220Vpp low noise electroluminescent lamp (EL) drivers designed to drive two panels of up to 4 square inches each. Applications include backlighting for mobile phones, personal multimedia players, portable navigation devices, and remote controls, as well as general lighting for automotive and industrial equipment. The ICs are available in volume with pricing starting at $1.14 for 1K quantities. Samples can now be ordered on line on Micrel's web site at: http://www.micrel.com/ProductList.do.
"The MIC4833/4 devices greatly reduce solution size for footprint-constrained applications that utilize multiple EL lamps," noted Andy Khayat, Micrel's marketing director for portable products. "The devices drive two EL lamps with only a single inductor and minimal number of external passive components, making the total solution size ideal for today's space- and cost-conscious battery-powered portable products."
The MIC4833 and MIC4834 achieve high efficiency, in part, by consuming a typical supply current of just 152 micro Amp. Utilizing Micrel's advanced Bipolar, CMOS, DMOS (BCD) technology, the ICs integrate a high voltage boost converter and a new H-bridge driver for driving a large EL lamp. In contrast to previous designs that often produced an annoying audible buzz, the new H-Bridge design eliminates this kind of noise by creating a smoother AC waveform across the EL panel. Operating from an input voltage range of 2.3V to 5.8V, the MIC4833/4 are suitable for 1-cell Li-Ion, and 2- or 3-cell Alkaline/NiCad/NiMH battery powered applications. Each EL driver is independently enabled and disabled; and brightness level adjustment for EL lamps is achieved by altering frequency of the EL oscillator internal to the device. The MIC4833 also includes an EL output slew rate control function to further reduce audible noise. The MIC4833 is available in a RoHS compliant 12-lead 3mm x 3mm MLF® package, and the MIC4834 is available in 10-lead 3mm x 3mm MLF® and 10-lead MSOP packages. All options feature a -40-degC to +125-degC junction temperature range.