CAT4240 Datasheet | Catalyst Semiconductor

.. 6 Watt Boost LED Driver Features - - - - - - - - - - - Switch Current Limit 750m A Drives High Voltage LED strings (38V) Up to 87% Efficiency Low Quiescent Ground Current 0.6m A 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, Digital Cameras ORDERING INFORMATION Part Number CAT4240TD-GT3 - Ni Pd Au Plated Finish Package TSOT23-5 Green- Quantity Package per Reel Marking 3000 TG For Ordering Information details, see page 13. Pin Configuration 5-Lead Thin SOT23 (1mm max height) SW 1 GND 2 FB 3 4 SHDN 5 VIN Typical Application Circuit VL 8V to 16V VIN 5V C1 L1 47µH 4.7µF/16V VIN SW D1 C2 1µF/50V VOUT C3 1µF CAT4240 SHDN GND FB (300m V) R2 1kΩ R1 1Ω 300m...