LM3631 Datasheet, PDF (1/57 Pages) Texas Instruments – Complete LCD Backlight and Bias Power

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LM3631 Complete LCD Backlight and Bias Power
LM3631
SNVS834 – AUGUST 2014
1 Features
•1 Drives up to Two Strings with Maximum of 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 Linear or Exponential Dimming with up to
17-Bit Output Resolution
• External PWM Input for CABC Backlight
Operation
• LCD Bias Efficiency > 85%
• Programmable Positive LCD bias, 4-V to 6-V,
100-mA Maximum Output Current
• Programmable Negative LCD bias, –4-V to –6-V,
80-mA Maximum Output Current
• Two Positive Programmable LDO Reference
Outputs
– 4-V to 6-V, 50-mA Maximum Output Current
– 1.8-V to 3.3-V, 80-mA Maximum Output
Current
• 2.7-V to 5-V Input Voltage Range
2 Applications
Mobile Device LCD Backlighting and Bias
3 Description
The LM3631 is a complete LCD backlight and bias
power solution for mobile devices. This one-chip
solution has an integrated high-efficiency backlight
LED driver and positive/negative bias supplies for
LCD drivers addressing the power requirements of
high-definition LCDs. Integrated solution allows small
solution size while still maintaining high performance.
Capable of driving up to 16 LEDs, the LM3631 is
ideal for small- to medium-size displays. Two
additional programmable LDO regulator outputs can
be used to power display controller, LCD gamma
reference, or any additional peripherals.
A high level of integration and programmability allows
the LM3631 to address a variety of applications
without the need for hardware changes. Voltage
levels, backlight configuration, and power sequences
are all configurable through I²C interface.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (MAX)
LM3631
DSBGA (24)
2.585 mm x 1.885 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
+
- ^VIN
Simplified Schematic
LSW
D1
CIN
LBST
CIN
Up to 8 LEDs / string
COUT
VIN
SW
VOUT
LED1
BST_SW
LED2
SDA
C2
SCL
nRST
LM3631
C1
BST_OUT
LCD_EN
CP_VNEG
PWM
LDO_OREF
OTP_SEL
LDO_VPOS
FLAG
LDO_CONT
GND_BST_SW
AGND
GND_SW
PGND
CFLY
VNEG (-5.4V)
VOREF (+4.0V to +6.0V)
VPOS (+5.4V)
VCONT (+1.8V)
CCONT CVPOS COREF CNEG CBST
Backlight Efficiency, 2P6S
95
90
85
80
75
70
65
60
VIN 2.7V
55
VIN 3.7V
VIN 5.0V
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.