LM3632A Datasheet, PDF (1/64 Pages) Texas Instruments – Single-Chip Backlight With Bias Power and 1.5-A Flash LED Driver

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LM3632A
SNVSA63A – APRIL 2015 – REVISED SEPTEMBER 2015
LM3632A Single-Chip Backlight With Bias Power and 1.5-A Flash LED Driver
1 Features
•1 Drives up to Two Strings of Typically Eight LEDs
in Series
– Integrated Backlight Boost with 29-V Maximum
Output Voltage
– Two Low-Side Constant-Current LED Drivers
with 25-mA Maximum Output Current
• Backlight Efficiency Up to 90%
• 11-Bit Exponential or Linear Dimming
• External PWM Input for CABC Backlight
Operation
• LCD Bias Efficiency > 85%
• Programmable Positive LCD bias, 4-V to 6-V, 50-
mA Maximum Output Current
• Programmable Negative LCD bias, –4-V to –6-V,
50-mA Maximum Output Current
• 1.5-A Flash LED Boost
• Flash Efficiency > 85%
• 2.7-V to 5-V Input Voltage Range
2 Applications
• Smart Phone LCD Backlighting and Bias
• Small Tablet LCD Backlighting and Bias
Simplified Schematic
D1
LBL
LFL
CIN
LLCM
VBATT
FL_SW FL_SW
VIN
BL_SW
BL_OUT
LCM_SW
SCL
SDA
BLED1
BLED2
FL_OUT
FL_OUT
STROBE
TX
LM3632
FLED
FLED
CBL_OUT
Up to 8 LEDs / String
CFL_OUT
PWM
EN
LCM_EN1
LCM_EN2
C1
C2
LCM_OUT
VPOS
CFLY
CLCM
AGND
VNEG
BL_GND CP_GND FL_GND LCM_GND
CVPOS
CVNEG
3 Description
The LM3632A integrates the WLED drivers for both
the backlight of the LCD panel and the camera flash
along with the bias power for the LCD panel into one
device. The device has all the safety features
required in LED drivers with up to 90% efficiency and
bias positive/negative power rails achieving 1.5%
accuracy. Capable of driving up to 16 backlight LEDs,
the device is ideal for small- to medium-size displays.
A 1.5-A constant-current LED driver powered by a
synchronous boost converter can be used for flash
applications. The high-side flash current source
allows for grounded cathode LED operation.
A high level of integration and programmability allows
the LM3632A to address a variety of applications
without the need for hardware changes.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (MAX)
LM3632A
DSBGA (30)
2.47 mm x 2.07 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
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Backlight Efficiency, 2P7S
95
90
85
80
75
70
65
60
V_IN = 2.7 V
55
V_IN = 3.7 V
V_IN = 5 V
50
0 5 10 15 20 25 30 35 40 45 50
Load (mA)
D007
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.