LM3464 Datasheet, PDF (1/33 Pages) National Semiconductor (TI) – 4 Channel LED Driver Evaluation Board

LM3464, LM3464A
www.ti.com
SNVS652F – APRIL 2010 – REVISED MAY 2013
LED Driver with Dynamic Headroom Control and Thermal Control Interfaces
Check for Samples: LM3464, LM3464A
FEATURES
1
•2 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
and Minimum Duty Cycle (Analog Dimming
Mode)
• Direct Interface to Thermal Sensor
• Fault Detection
• Over Temperature Protection
• Thermal Shutdown
• Under Voltage Lockout
• Thermal Enhanced TSSOP-28 Package
APPLICATIONS
• Streetlights
• Solid State Lighting Solutions
DESCRIPTION
The LM3464/64A is a 4-channel high voltage current
regulator that provides a simple solution for LED
lighting applications. The LM3464/64A provides four
individual current regulator channels and works in
conjunction with external N-channel MOSFETs and
sense resistors to give accurate driving current for
every LED string. Additionally, the Dynamic
Headroom Control (DHC) output can be interfaced to
the external 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 external capacitor. A minimum
duty cycle control is provided in the conditions that
the analog dimming is configured as thermal
feedback.
Protection features include VIN under-voltage lock-
out, LED open/short circuit and over-temperature fault
signaling to the system controller.
Typical Application
VRAIL
High Power LED Arrays
Voltage
output
RFB1
LM3464/64A
Primary power
supply
RDHC
Voltage
feedback pin
RFB2
CDHC
CFLT
PGND
VDHC
FAULTb
AGND
External voltage headroom control
Fault acknowledgement output
DIM
RTHM1
PWM dimming input
5V
0V
RTHM2
A
To NTC thermal
sensor
B
CVCC
RDMIN1
RDMIN2
CTHM
EN
VIN
OutP
VLedFB
CDHC
FAULT_CAP
DR1
DR2
DR3
DR4
GD1
SE1
GD2
SE2
VDHC
Faultb
DIM
VCC
GD3
SE3
GD4
SE4
Thermal
DMIN
Thermal_Cap SYNC
AGND PGND
Q1
Q2
Q3
Q4
RISNS1 RISNS2 RISNS3 RISNS4
PGND PGND PGND PGND
NTC thermistor
couple to LED
arrays
A _{To thermal}
sensor
terminals
B
AGND PGND
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.
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