LM36273 Datasheet, PDF (1/9 Pages) Texas Instruments – Integrated Backlight Driver With Integrated LCD Bias

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LM36273
SNVSA80A – FEBRUARY 2016 – REVISED FEBRUARY 2016
LM36273 Integrated Backlight Driver With Integrated LCD Bias
1 Features
•1 Drives up to Three Parallel White LED Strings
(29-V Maximum V_OUT)
• 11-Bit Exponential and Linear Dimming Control
• PWM and I²C Brightness Control
• Backlight Operation With 4.7-µH to 15-µH Inductor
• Backlight and LCD Bias Efficiency up to 92%
• Programmable LCD Bias Voltages (±4 V to ±6.5 V
With 50-mV resolution) With Up to 80-mA per
Output
• 0.2% Matched LED Current From 60 µA to 30 mA
• 1% Accurate LED Current From 60 µA to 30 mA
• 2.7-V to 5-V Input Voltage Range
2 Applications
• LCD Panels With up to 24 LEDs
• Smart Phones
• Tablets and Gaming Tablets
• Home Automation Panels
space
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Simplified Schematic
DSCH
LBL
CBL_OUT
IN
BL_OUT
LLCM
VBATT
LCM_SW
SCL
SDA
LM36273
PWM
HWEN
LED1
LED2
LED3
C+
C-
Up to 8 LEDs / String
CFLY
LCM_EN1
LCM_EN2
LCM_OUT
VPOS
VNEG
CLCM
CVPOS
CVNEG
3 Description
The LM36273 is an integrated three-channel WLED
driver and LCD bias supply. The ultra-compact size,
high efficiency, high level of integration, and
programmability allow the LM36273 to address a
variety of applications without the need for hardware
changes while minimizing the overall solution area.
The backlight boost provides the power to bias three
parallel LED strings with up to 29-V total output
voltage. The 11-bit LED current is programmable via
the I²C bus and/or controlled via a logic level PWM
input from 60 µA to 30 mA. Each LED string can be
independently enabled or disabled to provide zone
dimming capabilities. The backlight boost can be
operated efficiently with an inductance range from
4.7 µH to 15 µH, allowing for efficiency and solution
size optimization.
The LCD bias boost provides the power to both a
positive LDO and an inverting charge pump. Both
positive and negative bias supplies have
programmable output voltages of ±4 V to ±6.5 V with
50-mV steps and up to ±80 mA of current capability.
An auto-sequencing feature provides a programmed
delay from positive to negative bias activation, with
additional programmable voltage slew rate control.
Two wake-up modes allow both bias outputs to be
controlled with a single external signal and stay active
while consuming very low quiescent current.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (MAX)
LM36273
DSBGA (24)
2.44 mm × 1.67 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Backlight Efficiency, 3P7S
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 10 20 30 40 50 60 70 80 90
Load (mA)
D052
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.