LM3463 Datasheet, PDF (1/33 Pages) Texas Instruments – Dynamic Headroom Controller with Thermal Control Interface and Individual Channel Dimming Control

LM3463
May 11, 2012
Dynamic Headroom Controller with Thermal Control
Interface and Individual Channel Dimming Control
General 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 dis-
sipation 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 maximiz-
ing the system efficiency.
The dimming control interface of the LM3463 accepts both
analog and PWM dimming control signals. The analog dim-
ming control input controls the current of all LEDs while the
PWM control inputs control the dimming duty of output chan-
nels 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 protec-
tion and MOSFET drain voltage limiting. The LED short circuit
protection protects both the LED and MOSFETS by limiting
the power dissipation on the MOSFETS.
Features
■ ^{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}
Key Specifications
■ ^{Wide supply voltage range (12V-95V)}
■ ^{Thermal fold-back dimming control}
■ ^{DHC regulates the lowest MOSFET drain voltage to 1V}
Applications
■ ^Streetlights
■ ^{Solid State Lighting Solutions}
Typical Application
© 2012 Texas Instruments Incorporated 301757 SNVS807
30175790
www.ti.com