LM3464_10 Datasheet, PDF (1/22 Pages) National Semiconductor (TI) – LED Driver with Dynamic Headroom Control and Thermal Control Interfaces

LM3464/LM3464A
November 18, 2010
LED Driver with Dynamic Headroom Control and Thermal
Control Interfaces
General Description
The LM3464/64A is a 4-channel high voltage current regula-
tor that provides a simple solution for LED lighting applica-
tions. The LM3464/64A provides four individual current
regulator channels and works in conjunction with external N-
channel MOSFETs and sense resistors to give accurate driv-
ing current for every LED string. Additionally, the Dynamic
Headroom Control (DHC) output can be interfaced to the ex-
ternal power supply to adjust the LED supply voltage to the
lowest level that is adequate to maintain all the string currents
in regulation, yielding the optimal overall efficiency.
Digital PWM or analog voltage signals can be used to control
the duty cycle of the all the channels. When analog control is
used, the dimming frequency can be programmed via an ex-
ternal capacitor. A minimum duty cycle control is provided in
the conditions that the analog dimming is configured as ther-
mal feedback.
Protection features include VIN under-voltage lock-out, LED
open/short circuit and over-temperature fault signaling to the
system controller.
Features
■ ^{Wide input voltage range}
12V-80V (LM3464)
12V–95V (LM3464A)
■ ^{Dynamic Headroom Control ensures maximum efficiency}
■ ^{4 output channels with individual current regulation}
■ ^{High channel to channel accuracy}
■ ^{Digital PWM/Analog dimming control interface}
■ ^{Resistor programmable dimming frequency & minimum}
duty cycle (analog dimming mode)
■ ^{Direct interface to thermal sensor}
■ ^{Fault detection}
■ ^{Over temperature protection}
■ ^{Thermal shutdown}
■ ^{Under voltage lockout}
■ ^{Thermal enhanced eTSSOP-28 package}
Applications
■ ^Streetlights
■ ^{Solid State Lighting Solutions}
Typical Application
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