
Analog Devices
GENERAL DESCRIPTION
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
APPLICATIONS
Camera-enabled cellular phones and smart phones
Digital still cameras, camcorders, and PDAs