Analog Devices ADP1655
The ADP1655 is a very compact, highly efficient, dual white LED flash driver for high resolution camera phones, which improves picture and video quality in low light environments. The device integrates a 2 MHz synchronous inductive boost convertor, an I2C-compatible interface and a 500 mA current source. The high switching frequency enables the use of a tiny, low profile 2.2 μH power inductor, and the current source permits LED cathode grounding for thermally enhanced, low EMI and compact layouts.FEATURES
Ultracompact solution Small 2 mm × 1.5 mm 12-ball WLCSP package Tiny, low profile 2.2 μH power inductor LED current source for local LED grounding and low EMI Synchronous 2 MHz PWM boost convertor, no external diode High efficiency: 88% peak Reduces high levels of input battery current during flash Limits battery current drain in torch mode I2C programmable Currents up to 400 mA in flash mode for two LEDs Currents up to 500 mA in flash mode for one LED with 5% accuracy Currents up to 160 mA in torch mode with 10% accuracy Peak inductor current limit Flash timer Control I2C-compatible control registers External STROBE pin External direct TORCH pin TX_MASK input to prevent high input battery current levels Safety Thermal overload protection Flash timeout Inductor fault detection Output overvoltage Short circuit protection Soft start reduces inrush input current FUNCTIONAL BLOCK DIAGRAM INPUT VOLTAGE = 2.5V TO 5.5V 2.2µH 10µF STROBE VIN TORCH SW VOUT ADP1655 SCL/EN1 SDA/EN2 LED_OUT TX_MASK 10µF I2C/EN SGND PGND 08028-001 Figure 1.