7W Buck LED Driver Resides In TSOT-23

Housed in a 5-lead TSOT-23 package, the CAT4201 buck converter drives white LED strings up to 21V, regulates current up to 350 mA, and eliminates the need for a heat sink with efficiencies up to 94%. The chip relies on a patent-pending switching-control algorithm that reportedly reduces system complexity, improves efficiency and allows an external RSET control resistor to preset a regulated LED current up to 350 mA from supplies as high as 24V. The device is compatible with switching frequencies up to 1 MHz, and integrated load-dump protection handles transients up to 40V. It can drive one 1W LED from a 6V supply or up to seven LEDs in series from a 24V supply. A dedicated enable control using minimal input current allows the load to be disabled and placed into a zero-current shutdown mode. Other features include short-circuit and thermal-overload fault protection. Price for the CAT4201 is $0.72 each/10,000. CATALYST SEMICONDUCTOR INC., Sunnyvale, CA. (800) 258-5991.