MIC3289 Datasheet | Micrel Semiconductor

Description The MIC3289 is a PWM boost-switching regulator that is optimized for constant-current white LED driver applications. The MIC3289 features an internal Schottky diode, allowing an efficient DC/DC solution that requires only 4 external ponents. The MIC3289 allows for a single wire simple digital interface to control the dimming over 16 steps with a log scale to give better resolution at the lower currents to better match the sensitivity of the human eye The feedback voltage of the MIC3289 is only 250m V, allowing high efficiency while retaining excellent accuracy for the white LED current. The MIC3289 implements a constant frequency 1.2MHz PWM control scheme. The high frequency PWM operation saves board space by reducing external ponent sizes. The 1.2MHz PWM scheme also reduces switching noise and ripple to the input power source. The 2.5V to 6.5V input voltage range of MIC3289 allows direct operation from single cell Li Ion as well as 3- to 4cell Ni Cad/ Ni MH/Alkaline batteries. Battery life is preserved with a low 1µA shutdown current. The MIC3289 is available in a low profile Thin SOT23 6® lead package and a 2mm × 2mm MLF -8L package and has a junction temperature range of - 40°C to +125°C. Data sheets and support documentation can be found on Micrel’s web site at .micrel.. Features - - - - - - - - - - - - - - - 2.5V to 6.5V input voltage Output voltage up to 24V 16V & 24V OVP options Single wire bines 16 level logarithmic brightness & shutdown control Internal Schottky diode 1.2 MHz PWM operation Over 500m A switch current Programmable ±5% current control <1% line and load regulation <1µA shutdown current Over temperature protection UVLO Thin SOT23-6L package option ® 2mm × 2mm leadless MLF -8L package option o o - 40 C to +125 C junction temperature range Applications - White/Blue LED driver for backlighting - Cell phones - PDAs - GPS systems - Digital cameras - Multimedia / MP3 players - LED flashlights - Constant current power supplies ________________...