AP3019 Datasheet | BCD Semiconductor

Preliminary Datasheet WHITE LED STEP-UP CONVERTER General Description The AP3019 is an inductor-based DC/DC converter designed to drive up to five white LEDs in series for backlight. Only one feedback resistor is needed to control the LED current and obtain satisfied brightness. A constant frequency 1.0MHz PWM control scheme is employed in this IC, which means the tiny external ponents can be used. In fact, 1mm tall inductor and 0.22µF output capacitor for the typical application is very appropriate. Additionally, the schottky diode in boost circuit is integrated in this chip. AP3019 also provides a disable port to ease its use for different systems. The over output voltage protection is equipped in AP3019. When any LED is broken or in other abnormal conditions, the output voltage will be clamped to 27V. The AP3019 is available in standard SOT-23-6 package. .. AP3019 Features - - - - - - - - Inherently Uniform LED Current High Efficiency up to 84% No Need for Extra Schottky Diode Over Output Voltage Protection Drives 2 to 5 LEDs Fast 1.0MHz Switching Frequency Uses Tiny 1mm Tall Inductor Requires Only 0.22µF Output Capacitor Applications - - - - - Cellular Phones Digital Cameras LCD modules GPS Receivers PDAs, Handheld puters SOT-23-6 Figure 1. Package Type of AP3019 Apr. 2007 Rev. 1. 1 1 BCD Semiconductor Manufacturing Limited Preliminary Datasheet WHITE LED STEP-UP CONVERTER Pin Configuration K Package (SOT-23-6) VOUT GND FB 1 2 3 6 5 4 SW VIN CTRL Figure 2. Pin Configuration of AP3019 (Top View) Pin Description Pin Number 1 2 3 4 5 6 Pin Name SW GND FB CTRL VOUT VIN Switch Pin. Connect external inductor Ground Pin Voltage Feedback. Reference voltage is 200m V Shutdown and Dimming Pin. Connect to 1.8V or higher to enable device; Connect to 50m V or less to disable device; Connect to a voltage between 1.8V and 50m V to achieve linear dimming Output Pin. Connected to the cathode of internal schottky diode Input Supply Pin....