Driver. LP8545 Datasheet

LP8545 Datasheet PDF


Part

LP8545

Description

High-Efficiency LED Backlight Driver

Manufacture

etcTI

Page 30 Pages
Datasheet
Download LP8545 Datasheet


LP8545 Datasheet
LP8545
www.ti.com
SNVS635D – APRIL 2010 – REVISED DECEMBER 2013
High-Efficiency LED Backlight Driver for Notebooks
Check for Samples: LP8545
FEATURES
1
2 High-Voltage DC/DC Boost Converter with
Integrated FET with Four Switching Frequency
Options: 156/312/625/1250 kHz
• Configurable for Use with External FET for
Applications Needing Higher Output Voltage
• 2.7V – 22V Input Voltage Range to Support
1x…5x Cell Li-Ion Batteries
• Programmable PWM Resolution
– 8 to 13 True Bit (Steady State)
– Additional 1 to 3 Bits Using Dithering
During Brightness Changes
• I2C and PWM Brightness Control
• PWM Output Frequency and LED Current Set
Through Resistors
• Optional Synchronization to Display VSYNC
Signal
• 6 LED Outputs with LED fault (Short/Open)
Detection
• Low Input Voltage, Over-Temperature, Over-
Current Detection and Shutdown
• Minimum Number of External Components
• WQFN 24-Pin Package, 4 x 4 x 0.8 mm
APPLICATIONS
• Notebook and Netbook LCD Display LED
Backlight
• LED Lighting
DESCRIPTION
The LP8545 is a white LED driver with integrated
boost converter. It has six adjustable current sinks
which can be controlled by PWM input or with I2C-
compatible serial interface.
The boost converter has adaptive output voltage
control based on the LED driver voltages. This
feature minimizes the power consumption by
adjusting the voltage to lowest sufficient level in all
conditions.
LED outputs have 8-bit current resolution and up to
13-bit PWM resolution with additional 1-3 bit dithering
to achieve smooth and precise brightness control.
Proprietary Phase Shift PWM control is used for LED
outputs to reduce peak current from the boost
converter, thus making the boost capacitors smaller.
The Phase Shifting scheme also eliminates audible
noise.
Internal EEPROM is used for storing the configuration
data. This makes it possible to have minimum
external component count and make the solution very
small.
LP8545 has safety features which make it possible to
detect LED outputs with open or short fault. As well
low input voltage and boost over-current conditions
are monitored and chip is turned off in case of these
events. Thermal de-rating function prevents
overheating of the device by reducing backlight
brightness when set temperature has been reached.
LP8545 is available in TI's WQFN 24-pin package.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
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 © 2010–2013, Texas Instruments Incorporated

LP8545 Datasheet
LP8545
SNVS635D – APRIL 2010 – REVISED DECEMBER 2013
Typical Application (1)
VBATT 5.5V ± 22V
VDDIO reference voltage
VSYNC signal
100 nF
CVLDO 5V
1 éF
VDDIO
VSYNC
VLDO
VIN
L1
CIN 15 éH
10 éF
D1
GD SW
FB
1 éF 120 k#
RISET
RFSET
MCU
Can be left floating
if not used
FILTER
ISET
FSET
SCLK
SDA
PWM
EN
FAULT
LP8545
GNDs
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
10V ± 40V, 180 mA ± 400 mA
39 pF
COUT
4.7 éF
www.ti.com
Typical Application for Low Input Voltage (2)
2.7V ± 22V
VBATT 5.5V ± 22V
+5V input rail
1 éF
CVLDO
L1
CIN 15 éH
10 éF
D1
VDDIO reference voltage
VSYNC signal
100 nF
VDDIO VLDO
VSYNC
VIN
GD
1 éF 120 k#
RISET
RFSET
MCU
Can be left floating
if not used
FILTER
ISET
FSET
SCLK
SDA
PWM
EN
FAULT
LP8545
GNDs
SW
FB
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
10V ± 25V, 180 mA
10V ± 40V, 180 mA ± 400 mA
39 pF
COUT
4.7 éF
Note: Separate 5V rail to VLDO can be also used to improve efficiency for applications with higher battery voltage. No
power sequencing requirements between VIN/VLDO and VBATT.
2 Submit Documentation Feedback
Product Folder Links: LP8545
Copyright © 2010–2013, Texas Instruments Incorporated


Features Datasheet pdf LP8545 www.ti.com SNVS635D – APRIL 2 010 – REVISED DECEMBER 2013 High-Eff iciency LED Backlight Driver for Notebo oks Check for Samples: LP8545 FEATURES 1 •2 High-Voltage DC/DC Boost Conver ter with Integrated FET with Four Switc hing Frequency Options: 156/312/625/125 0 kHz • Configurable for Use with Ext ernal FET for Applications Needing High er Output Voltage • 2.7V – 22V Inpu t Voltage Range to Support 1x…5x Cell Li-Ion Batteries • Programmable PWM Resolution – 8 to 13 True Bit (Steady State) – Additional 1 to 3 Bits Usin g Dithering During Brightness Changes I2C and PWM Brightness Control • P WM Output Frequency and LED Current Set Through Resistors • Optional Synchro nization to Display VSYNC Signal • 6 LED Outputs with LED fault (Short/Open) Detection • Low Input Voltage, Over- Temperature, Over- Current Detection an d Shutdown • Minimum Number of Extern al Components • WQFN 24-Pin Package, 4 x 4 x 0.8 mm APPLICATIONS • Notebook and Netbook LCD Display LED Backlight • LED Lighting DESC.
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