LM3463_12 Datasheet, PDF (1/40 Pages) Texas Instruments – LM3463 Dynamic Headroom Controller with Thermal Control Interface and Individual Channel Dimming Control

LM3463
www.ti.com
SNVS807 – MAY 2012
LM3463 Dynamic Headroom Controller with Thermal Control Interface and Individual
Channel Dimming Control
Check for Samples: LM3463
FEATURES
1
•2 Dynamic Headroom Control output to
maximize efficiency
• 6 channels current regulated LED driver
• High precision analog dimming control
interface
• 4 individual PWM dimming control input
• Dimming control via digital data bus
• Built-in maximum MOSFET power limiting
mechanism
• Allows cascade operation to extend the output
channels
• Fault indicator output
• Thermal shutdown
• UVLO with hysteresis
• 48L LLP package
APPLICATIONS
• Streetlights
• Solid State Lighting Solutions
DESCRIPTION
The LM3463 is a six channel linear LED driver with Dynamic Headroom Control (DHC) interface that is
specialized for high power LED lighting applications. The variation of the output current of every output channel
in the temperature range of -40°C to 125°C is well controlled to less than ±1%. The output current of every
channel is accurately matched to each other with less than ± 1% difference as well.
By interfacing the LM3463 to the output voltage feedback node of a switching power supply via the DHC
interface, the system efficiency is optimized automatically. The dynamic headroom control circuit in the LM3463
minimizes power dissipation on the external MOSFETs by adjusting the output voltage of the primary switching
power supply according to the changing forward voltage of the LEDs. Comprising the advantages of linear and
switching converters, the LM3463 delivers accurately regulated current to LEDs while maximizing the system
efficiency.
The dimming control interface of the LM3463 accepts both analog and PWM dimming control signals. The analog
dimming control input controls the current of all LEDs while the PWM control inputs control the dimming duty of
output channels individually.
The LM3463 provides a sophisticated protection mechanism that secures high reliability and stability of the
lighting system. The protection features include V_IN Under-Voltage–Lock-Out (UVLO), thermal shut-down, LED
short / open circuit protection and MOSFET drain voltage limiting. The LED short circuit protection protects both
the LED and MOSFETS by limiting the power dissipation on the MOSFETS.
VALUE
Wide supply voltage range (12V-95V)
Thermal fold-back dimming control
DHC regulates the lowest MOSFET drain
voltage to 1V
Table 1. Key Specifications
UNIT
1
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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 © 2012, Texas Instruments Incorporated