MIC3289

www.DataSheet4U.com MIC3289 1.2MHz PWM White LED Driver with Internal Schottky Diode and True 1-Wire Digital Control PRELIMINARY INFORMATION General 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 components. 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 250mV, 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 component 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 NiCad/ NiMH/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 www.micrel.com. Features ...