202188A.pdf

PRODUCT SUMMARY
AAT2405
Six-Channel White LED Driver for LCD TV Edge Lighting
General Description
Features
The AAT2405 is a highly integrated, high efficiency white
LED backlight solution for large size LCD panels used in
LCD TVs. This device operates from a wide 10.8V to 28V
DC power source, making it ideal for operation with common 12V to 24V AC-DC power supplies used in LCD TV
panels.
• VIN Range: 10.8V – 28V
• 6 LED Current Sinks up to 250mA/ch
▪ ±1.5% Accuracy @ 25°C (100mA)
▪ ±1.5% Matching @ 25°C (100mA)
• Maximum LED Current Set Resistor
• Linear Current Sink Calibration Input
• External PWM Dimming
▪ PWM Input Defined Period
• 50Hz to 20kHz PWM Input Frequency Range
• Wide PWM Dimming Range
• Cascade Multiple ICs:
▪ PWM Signal Feed Through: PWMIN / PWMOUT
▪ Chip to Chip Phase Delay Tracking
▪ PWM Clock SYNC Function
▪ Regulated Sink Voltage Feedback: CSFBI / CSFBO
• Programmable PWM Phase Delay
▪ 0° to 180° User Set by Resistor
▪ Typical ±10% Accuracy
• IC/LED On/Off Enable
• Integrated Fault Detection
▪ Open LED (<0.3V)
▪ Short Circuit LED (>6V)
▪ Over-Temperature Protection
• Soft-Start to Minimize Inrush Current
• 44 Pin E-LQFP10 Package
• -40°C to +85°C Temperature Range
By controlling external power MOSFETs (such as the
Skyworks' AAT2490 high-voltage TrenchDMOS array),
the AAT2405 facilitates 6 current sink channels to provide precision constant-current drive for strings of white
LEDs, where the number of series-connected LEDs per
string is only limited by the system LED voltage supply.
Current in each backlight string and string-to-string
matching is controlled using I-Precise™ sensing and control circuitry, a novel on-chip method to accurately control drain current in external discrete power MOSFETs
independent of their construction and without the need
for precision sense resistors.
LED string dimming is achieved by applying an external
PWM signal to the AAT2405's PWMIN input pin. An internal clock and programmable phase delay function allow
accurate PWM phase adjustment to each current sink or
selectable banks of current sinks. The AAT2405 has signal feed through function outputs for PWM dimming and
the internal clock signals allow cascaded AAT2405 devices to successively synchronize for both channel phase
and timing. The AAT2405's constant current sinks may
be set for phase delays individually or in banks of 2 or 3
LED strings.
The AAT2405 provides a current sense feedback input
and output feed through function so the LED string voltage level can be fed back to an external high voltage
boost converter. This function permits as many AAT2405s
as needed to be cascaded from a single power source.
An additional ICSFB output enables accurate feedback
using generic SMPS converters.
Applications
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•
•
•
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Converting LCD TV CCFL to LED Backlighting
Large Size LCD TV Panels
LCD Monitors
Multiple String White LED Drive Applications
White LED Backlighting
An IC enable pin is provided as a master LED on/off
function that may be toggled by an external system controller.
The AAT2405 provides an active low fault output. If an
LED short or open circuit is detected or if an over-temperature condition arises, the fault is reported on the FAULT
pin. Thermal protection circuitry shuts down the current
sinks in the event of an over-temperature condition.
The AAT2405 is available in the Pb-free 44 pin 10x10mm
E-LQFP package with exposed pad.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202188A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 18, 2012
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PRODUCT SUMMARY
AAT2405
Six-Channel White LED Driver for LCD TV Edge Lighting
Ordering Information
Package
Marking1
Part Number (Tray)2
E-LQFP10-44
XXYY 2405
AAT2405ISF-P1
Skyworks Green™ products are compliant with
all applicable legislation and are halogen-free.
For additional information, refer to Skyworks
Definition of Green™, document number
SQ04-0074.
Package Information
E-LQFP10-44
All dimensions in millimeters.
1. XXYY = assembly and date code.
2. Sample stock is generally held on part numbers listed in BOLD.
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Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202188A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 18, 2012
PRODUCT SUMMARY
AAT2405
Six-Channel White LED Driver for LCD TV Edge Lighting
Copyright © 2012 Skyworks Solutions, Inc. All Rights Reserved.
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Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
202188A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 18, 2012
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