CAT4240

www.DataSheet4U.com CAT4240 6 Watt Boost LED Driver FEATURES „ „ „ „ „ „ „ „ „ „ „ Switch Current Limit 750mA Drives High Voltage LED strings (38V) 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 Thin SOT23 5-Lead (1mm max height) DESCRIPTION The CAT4240 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 CAT4240 high-voltage output stage is perfect for driving mid-size and large panel displays containing up to ten white LEDs in series. 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 thin SOT23 package for space critical applications. APPLICATIONS „ GPS Navigation Systems „ Portable Media Players „ Handheld Devices, Di...