LED Driver From Supertex Drives a Single Low Current LED Across Wide Input Voltage Range

  Supertex, Inc. (NASDAQ: SUPX) today introduced HV9821, a clamped-mode, high-side buck converter IC for driving a low-voltage LED load at constant current programmable up to 50mA (or higher, as permitted by power dissipation, etc.). It is well suited for LED backlighting of push-buttons, switches and other automation control applications.

The IC limits peak voltage at its switching output to a level programmed by connecting an external Zener diode. This feature ensures a reasonable on-time of the switch, while minimizing the conduction power loss in HV9821. Power dissipation in the IC can be maintained below a chosen maximum level by selecting an adequate voltage clamp level VZ. HV9821 operates with fixed off-time, programmable externally with a resistor.

"HV9821 features programmable clamped-mode switching, which provides single LED operation from a high-voltage input with heat dissipation in the IC minimized," states Alex Mednik, Application Engineering Director at Supertex. "To accommodate that, HV9821 is packaged in a special 19-lead DFN, providing excellent thermal properties and high-voltage isolation."

HV9821 is available in a lead(Pb)-free/RoHS compliant 19L (7x5) DFN package (HV9821K7-G). Samples are available from stock. Lead-time for production quantities is 4-6 weeks, ARO. Pricing is US$1.05, in 1K quantities.

About Supertex Supertex, Inc. is a publicly held mixed signal semiconductor manufacturer, focused in high voltage analog and mixed signal products for use in the medical, LED lighting, printer and display, industrial and telecommunication industries. Supertex product, corporate and financial information is readily available at www.supertex.com.

Corporate Headquarters: Christine Mahiya Manager, Marketing Communications 408/222-4858 [e-mail]