TPS61176 Datasheet, PDF (1/28 Pages) Texas Instruments – High-Efficiency 6-Channel WLED Driver Supporting Single-Cell Li-Ion Battery Input

TPS61176
www.ti.com
SLVSBM5 – DECEMBER 2012
High-Efficiency 6-Channel WLED Driver Supporting Single-Cell Li-Ion Battery Input
Check for Samples: TPS61176
FEATURES
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• 2.7V to 6.5V VIN Voltage Range
• 2.7V to 24V Boost Input Voltage Range
• Integrated 2A/40V MOSFET
• 1MHz Switching Frequency
• Adaptive Boost Output to WLED Voltages
• Six Current Sinks of 35mA Capability Each
• ±2% (Max) Current Accuracy
• 1.3% (Typ) Current Matching
• Wide PWM Dimming Frequency Range
– from 100Hz to 22kHz
• Mixed Dimming Mode: Automatic Switch
between Analog Dimming and PWM Dimming
– Programmable Switch Point: 25% / 12.5%
– Programmable PWM Dimming Mode: 22kHz
PWM Dimming / Direct PWM Dimming
• Up to 14-bit Dimming Resolution
• Support down to 1% Dimming Duty Cycle
• Input PWM Glitch Filter
• Up to 90% Efficiency
• Driver for Input / Output Isolation PFET for
True Shutdown
• Built-in Soft Start
• Built-in WLED Open / Short Protection
• Thermal Shutdown
• Support 4.7µH Inductor
• 16L 3 mm x 3 mm QFN package
APPLICATIONS
• Tablet Backlight
• Notebook Backlight
• Backlight for Small and Media Form Factor
LCD Display with Single-Cell or Multi-Cell
Battery Input
DESCRIPTION
The TPS61176 is a highly integrated multi-channel
WLED backlight driver for tablet or notebook PCs,
which can support single-cell battery input directly. It
comprises a high efficient boost converter with an
integrated 2A/40V power MOSFET and six current
sink regulators. In total, the device can drive up to 60
WLEDs with high current matching performance. In
addition, the boost automatically adjusts its output
voltage to the WLED forward voltage to improve
efficiency.
TPS61176 adopts mixed dimming mode. The
automatic switch between PWM dimming at low
dimming duty cycle and analog dimming at high
dimming duty cycle increases the overall electrical-to-
optical efficiency, reducing the power budget for
backlight remarkably. The switch point can be
programmed to 12.5% or 25% and the PWM dimming
mode can be programmed to fixed frequency
dimming or direct PWM dimming. TPS61176 supports
up to 14-bit dimming resolution, which avoids
potential flickering perception during the low
brightness dimming.
By providing a driver for an external isolation P-
channel MOSFET, TPS61176 can support true
shutdown. When the IC is disabled or the boost
output is short to ground, the isolation PFET can be
turned off to cut off the power path from battery to the
WLEDs, preventing any leakage current from the
battery. TPS61176 also integrates soft start, WLED
open and short protection and thermal shut down.
TPS61176 is in a 16 pin 3mm x 3mm QFN package,
providing a space-saving and high-performance
WLED driver solution.
TYPICAL APPLICATION
2.7V ~ 6.5V
VIN
C1
2.2uF
R2
1.3M
C3
1uF
PWM
R1
51k
L1
4.7uH
D1
C2
SW 4.7uF
MODE / FAULT
PGND
R3
1M
OVP
VIN
R4
TPS61176
43k
VLDO
PWM / EN
ISET
GND
IFB1
IFB2
IFB3
IFB4
IFB5
IFB6
COMP
C4
0.47uF
Up to 38V
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2012, Texas Instruments Incorporated