Sunnyvale, Calif. Catalyst Semiconductor, Inc. has introduced a family of buck converters that drives white LED strings up to 21 volts in a TSOT-23 package. The CAT4210 drives high-brightness, 350 mA LEDs at up 94 percent efficiency.
The CAT4201 can drive one 1W LED from a 6-V supply or up to 7 LEDs in series from a 24-V supply. A dedicated enable control using minimal input current allows the load to be disabled and placed into a zero current shutdown mode, eliminating battery drain when not in use. Protection against short-circuit and thermal over-load fault conditions is also included.
The first device in a new family of buck converters, the CAT4402 incorporates Catalyst's patent-pending switching control algorithm. This new architecture is said to reduce system complexity, improve efficiency and allow an external RSET control resistor to preset a regulated LED current up to 350 mA from supplies as high as 24 volts, to provide better inductor control and eliminate the need for a dedicated heat sink.
The CAT4201 buck converter is an alternative to linear regulators for driving high-brightness LEDs in step-down applications. A built-in load dump protection allows transients of 40 volts to be safely handled, which makes the driver suitable for automotive indicator and illumination lighting applications, including turn signal, brake and map reading lights.
Pricing: $0.72 each in quantities of 10,000
Availability: Samples are available now. Projected lead-time for production quantities is six to eight weeks ARO.
Product information: CAT4201
Catalyst Semiconductor, 1-408-542-1000, www.catsemi.com