LM3697_15 Datasheet, PDF (1/43 Pages) Texas Instruments – High-Efficiency Three-String White LED Driver

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LM3697
SNOSCS2C – NOVEMBER 2013 – REVISED OCTOBER 2015
LM3697 High-Efficiency Three-String White LED Driver
1 Features
•1 Drives Three Parallel High-Voltage LED Strings
for Display and Keypad Lighting
• High-Voltage Strings Capable of up to 40-V
Output Voltage and up to 90% Efficiency
• Up to 30 mA per Current Sink
• 11-Bit Configurable Dimming Resolution
• PWM Input for Content Adjustable Brightness
Control (CABC)
• Fully Configurable LED Grouping and Control
• Integrated 1-A/40-V MOSFET
• Adaptive Boost Output to LED Voltages
• Selectable 500-kHz and 1-MHz Switching
Frequency
• Four Configurable Overvoltage Protection
Thresholds (16 V, 24 V, 32 V, and 40 V)
• Overcurrent Protection
• Thermal Shutdown Protection
• 29-mm² Total Solution Size
2 Applications
• Power Source for Smart Phone Illumination
• Display, Keypad and Indicator Illumination
VIN = 2.7V to 5.5V
VIN
Simplified Schematic
L
D1
CIN
VOUT up to 40V
COUT
IN
SDA
SCL
HWEN
PWM
SW
OVP
HVLED1
HVLED2
HVLED3
PGND
3 Description
The LM3697 11-bit LED driver provides high-
performance backlight dimming for 1, 2, or 3 series
LED strings while delivering up to 90% efficiency. The
boost converter with integrated 1-A, 40-V MOSFET
automatically adjusts to LED forward voltage to
minimize headroom voltage and effectively improve
LED efficiency.
The LM3697 is a high-efficiency three-string power
source for backlight or keypad LEDs in smart-phone
handsets. The high-voltage inductive boost converter
provides the power for three-series LED strings for
display backlight and keypad functions (HVLED1,
HVLED2 and HVLED3).
An additional feature is a pulse width modulation
(PWM) control input for content adjustable backlight
control, which can be used to control any high-
voltage current sink.
The LM3697 is fully configurable via an I²C-
compatible interface. The device operates over a
2.7-V to 5.5-V input voltage range and a −40°C to
85°C temperature range.
Device Information(1)
ORDER NUMBER
PACKAGE
BODY SIZE (MAX)
LM3697YFQ
DSBGA (12)
1.64 mm x 1.29 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
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Boost Efficiency
Three String, L=22µH, 1MHz
92%
90%
88%
86%
84%
82%
80%
78%
76%
3s3p
4s3p
74%
5s3p
72%
70%
6s3p
7s3p
2.5 3 3.5 4 4.5 5 5.5
VIN (V)
C049
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.