MIC3289-24YD6-TR Microchip

MIC3289 1.2MHz PWM White LED Driver with Internal Schottky Diode and True 1-Wire Digital Control General Description Features The MIC3289 is a PWM boost-switching regulator that is Single wire combines 16 level logarithmic brightness & optimized for constant-current white LED driver shutdown control applications. The MIC3289 features an internal Schottky 16V / 24V OVP options supports up to 4 & 6 WLEDs diode, allowing an efficient DC/DC solution that requires Start-up in any one of 16 brightness levels only 4 external components. Internal Schottky diode The MIC3289 allows for a single wire simple digital 2.5V to 6.5V input voltage interface to control the dimming over 16 steps with a log scale to give better resolution at the lower currents and to 1.2 MHz PWM operation better match the sensitivity of the human eye. The pre- Over 500mA switch current programming feature allows the user to select any one of 250mV reference voltage the 16 WLED current levels as the start-up brightness 5% LED current accuracy level. <1A shutdown current The feedback voltage of the MIC3289 is only 250mV, Over temperature protection allowing high efficiency while retaining excellent accuracy for the white LED current. UVLO The MIC3289 implements a constant frequency 1.2MHz Thin SOT23-6L package option PWM control scheme. The high frequency PWM operation 2mm 2mm leadless MLF -8L package option saves board space by reducing external component sizes. o o 40 C to +125 C junction temperature range 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 Applications direct operation from single cell Li Ion as well as 3- to 4- White/Blue LED driver for backlighting cell NiCad/NiMH/Alkaline batteries. Battery life is preserved with a low 1A shutdown current. - Cell phones - PDAs The MIC3289 is available in a low profile Thin SOT23 6- lead package and a 2mm 2mm MLF -8L package and - GPS systems has a junction temperature range of 40C to +125C. - Digital cameras Data sheets and support documentation can be found on - Multimedia / MP3 players Micrels web site at www.micrel.com. LED flashlights Constant current power supplies MicroLead Frame and MLF are registered trademarks of Amkor Technologies. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC3289 Typical Application MIC3289 2mm2mm MLF Digital Control 0.27F White LED Driver with OVP and Digital Control Ordering Information Part Number Marking Output Over Voltage Junction Temp. Package Code Voltage Protection Range MIC3289-16YD6 WF16 Adjustable 16V -40C to 125C TSOT23-6 MIC3289-24YD6 WF24 Adjustable 24V TSOT23-6 -40C to 125C MIC3289-16YML WFA Adjustable 16V -40C to 125C 2x2 MLF -8L MIC3289-24YML WFB Adjustable 24V -40C to 125C 2x2 MLF -8L Pin Configuration OUT 1 8GND VIN 2 7 SW SW 1 6 OUT DC 3 6 FB GND 2 5 VIN GND 4 5 NC 3 4 DC FB 2mm 2mm 8-pin MLF (ML) TSOT23-6 (D) M9999-061807 June 2007 2 (408) 944-0800