The EV1529DR-00A evaluation board is designed to drive 2 strings of up to 4 backlight LEDs to 30mA and a 4-LED flash string to 150mA from a single Lithium-Ion battery. The board is set up to obtain 20mA backlight current, 40mA preview current and 100mA flash current. All the LED currents can be adjusted by resistors RS1, RS2, and RS3 on the evaluation board.
The MP1529 switches at 1.2MHz and allows the use of tiny, low cost capacitors and small inductors. High frequency PWM dimming is made possible through EN1. The MP1529 includes built-in open-LED over-voltage protection, cycle-by-cycle current limit, over-temperature shutdown, input under-voltage control and integrated soft-start.
Product Features""• High Efficiency • 2.7V to 4.2V Input Voltage Range • Tiny Capacitors and Inductors Due to 1.2MHz Fixed Frequency Operation • LCD Backlight to 30mA, Flash to 150mA • Independent Backlight, Preview and Flash Current Adjustment • High Frequency PWM Dimming • Surface-Mount Components • Fully Assembled and Tested""
2.7V-5.5Vin, 25Vout, 3-Channel Boost WLED Driver Plus Flash Light
The MP1529 is a step-up converter for driving two 6LED backlight strings to 30mA and a 4LED flash string to 150mA from a single Lithium-Ion battery. The step-up converter generates an output voltage as high as 25V from a 2.7V to 5.5V input source. Three current sources drive in three modes. In backlight mode two strings of 6 LEDs are lit with up to 30mA of current. In the backlight plus preview mode the 4 flash LEDs are lit with the preview current. In flash mode the flash LEDs are lit with up to 150mA of current and the two backlight strings are turned off. There are three pins to independently set the backlight, preview and flash current. The MP1529 includes built-in open lamp over voltage protection, cycle-by-cycle current limit, over temperature shutdown, input under voltage control and integrated soft-start. The MP1529 is available in a tiny 16-pin 4mm x 4mm package.