CAT4139 Datasheet | Catalyst Semiconductor

.. 22V High Current Boost White LED Driver Features - - - - - - - - - - - Switch Current Limit 750m A Drives LED strings up to 22V 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 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 ORDERING INFORMATION Part Number Package CAT4139TD-GT3 TSOT23-5- - Ni Pd Au Plated Finish, Ro HS pliant For Ordering Information details, see page 12. PIN CONFIGURATION TSOT-23 5-Lead SW GND FB 1 2 3 4 SHDN 5 VIN TYPICAL APPLICATION CIRCUIT VIN 5V C1 SW VIN CAT4139 OFF ON SHDN GND FB (300m V) L 22µH C2 1µF 35V R2 1kΩ IOUT 180m A R1 1.62Ω D VOUT 9 strings at 20m A 4.7µF Top View L: Sumida CDRH6D28-220 D: Central CMSH1-40 (rated 40V) © Catalyst Semiconductor, Inc. Characteristics subject...