AX2012

AX2012 1.9A Fixed Frequency White LED Driver  GENERAL DESCRIPTION The AX2012 is a step-up converter designed for driving up to 8 series white LEDs for backlighting application. The AX2012 uses current mode, 1.2MHZ fixed frequency architecture to regulate the LED current, which is set through an external current sense resistor. Its low 300mV feedback voltage reduces power loss and improves efficiency. The OV pin monitors the output voltage and turns off the converter if an over-voltage condition is present due to an open circuit condition. The AX2012 includes under-voltage lockout, current limiting and thermal shutdown protection preventing damage in the event of an output overload. The driver is available in small 6-pin TSOT-23 and 8-pin TDFN (2mm x 2mm) packages.  FEATURES 2.5V to 5.5 V operating input voltage range Drives up to 8 series White LEDs 1.2MHz Fixed Switching Frequency Wide range for PWM dimming Ñb€ (200Hz to 200KHz) y R ` Internal 1.9A switching w current limit m Û V Over Voltage Protection (OVP) .com h Internal Soft-start Functiontec o of shutdown protection g Current limit and Thermal . ww Under voltage wLockout Available in the 6-pin TSOT-23 and 8-pin TDFN Packages 1/11 AX2012  BLOCK DIAGRAM VCC EN UVLO Reference 1.238V Soft Start Enable Logic 10ms OVP Shutdown OV 300mV FB Error Amplifier Summing Comparator Thermal Shutdown LX Control and Driver Logic N-MOS Oscillator 1.2MHz GND Slope Compensation Current Sense  PIN ASSIGNMENT The packag...