FN8372 Rev 0.00 Page 1 of 2
November 19, 2012
FN8372
Rev 0.00
November 19, 2012
ISL97900
RGB Buck-Boost 3-Channel Color Sequencing LED Driver
DATA SHORT
To request the full datasheet, please visit www.intersil.com/products/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
2C 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
LED2
L2
EN3
LED1
LED3
SGND
R1
0.1
EN2
2.8V TO 4.3V
EN1
C1
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)
C3
22µF
C11
22µF
C2
10µF
C4
22µF
C10
1µF
C7
0.1µF
C6
10µF
C5
1µF
SDA
LCoS
DRIVER ASIC
1.8V
PGND
PGND
FN8372 Rev 0.00 Page 2 of 2
November 19, 2012
ISL97900
Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted
in the quality certifications found at www.intersil.com/en/support/qualandreliability.html
Intersil products are sold by description only. Intersil may modify the circuit design and/or specifications of products at any time without notice, provided that such
modification does not, in Intersil's sole judgment, affect the form, fit or function of the product. Accordingly, the reader is cautioned to verify that datasheets are
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