CAT4139

www.DataSheet4U.com CAT4139 22V High Current Boost White LED Driver FEATURES „ „ „ „ „ „ „ „ „ „ „ Switch Current Limit 750mA Drives LED strings up to 22V Up to 87% Efficiency Low Quiescent Ground Current 0.6mA 1MHz Fixed Frequency Low noise Operation Soft start “in-rush” current limiting Shutdown current less than 1μA Open LED Overvoltage Protection Automatic Shutdown at 1.9V (UVLO) Thermal overload protection TSOT-23 5-Lead (1mm max height) DESCRIPTION The CAT4139 is a DC/DC step-up converter that delivers an accurate constant current ideal for driving LEDs. Operation at a fixed switching frequency of 1MHz allows the device to be used with small value external ceramic capacitors and inductor. LEDs connected in series are driven with a regulated current set by the external resistor R1. The CAT4139 is ideal for driving parallel strings of up to five white LEDs in series or up to 22V. LED dimming can be done by using a DC voltage, a logic signal, or a pulse width modulation (PWM) signal. The shutdown input pin allows the device to be placed in power-down mode with “zero” quiescent current. In addition to thermal protection and overload current limiting, the device also enters a very low power operating mode during “Open LED” fault conditions. The device is housed in a low profile (1mm max height) 5-lead TSOT-23 package for space critical applications. Quantity Package per Reel Marking 3000 TP APPLICATIONS „ GPS Navigation Systems „ Portable Media Players „ Handheld Devices...