Overview: WD3148
White LED Driver with PWM Brightness Control in Tiny Package WD3148
Http://www.sh-willsemi.com With a 40-V rated integrated power switch MOSFET, the WD3148 is a boost converter that drives up to 10 White LEDs in series. The WD3148 operates at 600kHz fixed switching frequency to reduce output ripple, improve conversion efficiency, and allows for the use of small external components. FB 1 COMP 2 GND 3 6 VIN 5 EN 4 LX The default Full-Scale White LED current is set by an external sensor resistor with regulated 200mV feedback voltage, as shown in typical application. During operation, the LED current can be controlled using the Pulse Width Modulation (PWM) signal applied on the EN pin, through which the PWM Duty-Cycle determines the feedback reference voltage and then the White LED current. In PWM mode, the WD3148 does not burst the LED current; therefore, it does not generate audible noises on the ceramic output capacitor.
