MIC2289C

MIC2289C White LED Driver Internal Schottky Diode and OVP General Description The MIC2289C is a PWM (pulse width modulated), boostswitching regulator that is optimized for constant-current white LED driver applications. The MIC2289C features an internal Schottky diode and three levels of output overvoltage protection providing a small size and efficient DC/DC solution that requires only four external components. To optimize efficiency, the feedback voltage is set to only 95mV. This reduces power dissipation in the current set resistor and allows the lowest total output voltage, hence minimal current draw from the battery. The MIC2289C implements a constant frequency 1.2MHz PWM control scheme. The high frequency, PWM operation saves board space by reducing external component sizes. The added benefit of the constant frequency PWM scheme in caparison to variable frequency is much lower noise and input ripple injected to the input power source. The MIC2289C clamps the output voltage in case of open LED conditions, protecting itself and the output capacitor. The MIC2289C is available with an output OVP option of 34V. The MIC2289C is available in low profile 6-pin Thin SOT23 package. The MIC2289C 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 2.5V to 10V input voltage Output voltage up to 34V with OVP Internal Schottky diode 1.2 MHz PWM operation Over 500mA switch c...