The ISL97901 is a highly efficient four channel, 1.5A
sequential LED driver powered from a single-cell Li-ion battery,
or regulated input voltage up to 5.5V. The ISL97901
incorporates an independent current controlled driving
mechanism for each of the LED's to allow accurate brightness
control.
The ISL97901 also utilizes a buck-boost converter to ensure
optimum output voltage is maintained for a wide variety of
LED forward voltages. The ISL97901's highly integrated and
efficient power conversion core operates at well over 90%
efficiency across a wide range of operating conditions. The
power conversion core implements a proprietary algorithm
that allows seamless transitions and glitch-free operation
between the buck and the boost modes as the battery voltage
drops during operation.
The ISL97901 provides I/O pins to interface with Intersil's
optical sensor IC's for white balance control. White balance is
achieved by closing the opto-electrical loop which allows for
LED light output to get calibrated against preset target values.
The ISL97901 can also be configured to run in an open-loop
manner if real-time white balance control is not desired. In this
case, the LED currents are set by the internal registers.

Features
• Buck-Boost Based LED Driver
• RGB, RGGB or RGBW Color Sequencing
• Up to 1.5A Output Current
• Photo Detector Feedback Interface
• Dual Green LED Drive Support
• Closed-Loop White Balancing Dynamic Current Scaling
• Standby Current less than 70µA
• I2C Interface
• 150mV Feedback Voltage Reference for Current Regulation
to Maximize Efficiency
• 2.5MHz Switching Frequency
• Programmable Output Voltage for each LED
• Dynamic Headroom Management
• Internal Current Setting Registers
• Ambient Temperature Range: 0°C to +70°C
• Pb-Free (RoHS Compliant)

Applications
• LED-Based Pico Projector In Mobile Phones
• Stand Alone Pico Projectors
• Tri-Stimulus Display Drivers
• Other Handheld Display Drivers