1
DATASHEET
To request the full datasheet, please visit www.intersil.com/products/isl97900
RGB Buck-Boost 3-Channel Color Sequencing LED
Driver
ISL97900
The ISL97900 is a highly efficient 3-channel, 1.5A sequential
LED driver powered from a single-cell Li-ion battery, or
regulated input voltage up to 5.5V. This LED driver incorporates
an independent current controlled driving mechanism for each
of the LED's, which allows accurate current control of the LED
brightness.
The ISL97900 utilizes a buck-boost converter to ensure that
optimum output voltage is maintained for a wide range of LED
forward voltages. The integrated buck-boost converter
operates 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 ISL97900 architecture includes a 10-bit DAC, which
controls the LED currents. Each of the LED currents can be
programmed through serial interface.
The ISL97900 also includes the Dynamic Headroom
Management function to provide seamless adjustment for the
LEDs’ voltages, which reduces power consumption.
Features
• Buck-boost based LED driver
•RGB color sequencing
•Up to 1.5A output current
•I
2
C Interface
• 150mV feedback voltage reference for current regulation to
maximize efficiency
• 2.5MHz switching frequency
• Programmable output voltage and output current 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
SCL
BATT
CEN
LED
2
L
2
EN3
LED
1
LED
3
SGND
R
1
0.1
EN2
2.8V TO 4.3V
EN1
C
1
22µF
2.2µH
1
2
3
4
5
6
7
8
28
22
21
20
19
18
17
15
16
EN1
27
26
25
24
23
9
10
11
12
13
14
EN2
EN3
GND
NC
NC
PVIN
PVIN
ADDR
VCC
SCL
SDA
CEN
LX1
CBYP
SGND
NC
LX2
VOUT
VOUT
LED1
LED2
LED3
NC
SGND
FB
THERMAL
PAD
(GND)
C
3
22µF
C
11
22µF
C
2
10µF
C
4
22µF
C
10
1µF
C
7
0.1µF
C
6
10µF
C
5
1µF
SDA
LCoS
DRIVER ASIC
1.8V
PGND
PGND
November 19, 2012
FN8372.0
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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| Copyright Intersil Americas Inc. 2012. All Rights Reserved
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All other trademarks mentioned are the property of their respective owners.
