1
DATASHEET
To request the full datasheet, please visit www.intersil.com/products/isl97901
RGB Buck-Boost Four-Channel LED Driver with Color
Sequencing and Automatic White Balance
ISL97901
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.
Related Literature
• ISL58333 “Wide Optical Spectrum Photo Sensor IC”
• ISL58344
“Quad Segment Photo Sensor IC”
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
•I
2
C 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
FIGURE 1. TYPICAL APPLICATION
ISL97901
FB2
SDA
LX1
EN1
LFBN
D1
VIN
Batt
D2
CEN
LED
2
VOUT
SCL
D3
PHOTO DETECTOR
ISL58333
C
1
LX2
EN3
LED
1
LED
3
SGND
SENSOR
C
2
47µF
R
SNS
0.1
EN2
LCoS OR DLP
DRIVER ASIC
2.7V TO 4.3V
D4
EN4
WHITE
OR
2
nd
GREEN
LED
4
ENABLE
DISABLE
LFBP
C
4
0.1µF
CBYP
FB1
R
SNS
0.1
PGND
ADDR
SDA
SCL
PGND
VOUT
VIN
VCC
C
3
1.0µF
2.2µH
20-40µF
June 29, 2012
FN7824.0
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
| Copyright Intersil Americas Inc. 2012. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
