LM36923H Datasheet, PDF (1/47 Pages) Texas Instruments – Highly Efficient Triple-String White LED Driver

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LM36923H
SNVSAF3A – FEBRUARY 2016 – REVISED FEBRUARY 2016
LM36923H Highly Efficient Triple-String White LED Driver
1 Features
•1 1% Matched Current Sinks Across Process,
Voltage, Temperature
• 3% Current-Sink Accuracy Across Process,
Voltage, Temperature
• 11-Bit Dimming Resolution
• Up to 90% Solution Efficiency
• Drives from One to Three Parallel LED Strings at
up to 38 V at 25 mA per String
• PWM Dimming Input
• I²C Programmable
• Selectable 500-kHz and 1-MHz Switching
Frequency With Optional –12% shift
• Auto Switch Frequency Mode (250 kHz, 500 kHz,
1 MHz)
• Four Configurable Overvoltage Protection
Thresholds (17 V, 24 V, 31 V, 38 V)
• Four Configurable Overcurrent Protection
Thresholds (750 mA, 1000 mA, 1250 mA,
1500 mA)
• Thermal Shutdown Protection
• Externally Selectable I²C Address Options via
ASEL Input
2 Applications
• Power Source for Smart Phone and Tablet
Backlighting
• LCD Panels With up to 24 LEDs
3 Description
The LM36923H is an ultra-compact, highly efficient,
three-string white-LED driver designed for LCD
display backlighting. The device can power up to 12
series LEDs at up to 25 mA per string. An adaptive
current regulation method allows for different LED
voltages in each string while maintaining current
regulation.
The LED current is adjusted via an I²C interface or
through a logic level PWM input. The PWM duty cycle
is internally sensed and mapped to an 11-bit current
thus allowing for a wide range of PWM frequencies
with noise-free operation from 50 µA to 25 mA.
Other features include an auto-frequency mode,
which can automatically change the frequency based
on load current in order to optimize efficiency.
The device operates over the 2.5-V to 5.5-V input
voltage range and a –40°C to +85°C temperature
range.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (MAX)
LM36923H
DSBGA (12)
1.756 mm × 1.355 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
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Simplified Schematic
VOUT (Up to 38V)
Typical String-to-String Matching vs LED Current
VBATT
VIO
SW
OVP
IN
LM36923H
HWEN
SDA
SCL
ASEL
PWM GND
LED1
LED2
LED3
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.