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SYNC

DR1

GD1

SE1

VDHC

OutP

VLedFB

CDHC

Faultb

FAULT_CAP

VCC

DIM

Thermal

DMIN

Thermal_Cap

AGND PGND

EN VIN

PGND

DR2

GD2

SE2

DR3

GD3

SE3

DR4

GD4

SE4

FLT

AGND

Primary power

supply

Voltage

feedback pin

RAIL

Voltage

output

Fault acknowledgement output

FAULTb

DIM

PWM dimming input

DHC

FB1

FB2

High Power LED Arrays

ISNS1

ISNS2

ISNS3

ISNS4

DHC

THM1

VCC

THM2

THM

DMIN2

DMIN1

PGND PGND PGND

PGND

NTC thermistor

couple to LED

arrays

To NTC thermal

sensor

To thermal

sensor

terminals

External voltage headroom control

VDHC

LM3464/64A

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

DESCRIPTION

The LM3464/64A is a 4-channel high voltage current

• Wide Input Voltage Range

regulator that provides a simple solution for LED

– 12V-80V (LM3464)

lighting applications. The LM3464/64A provides four

– 12V-95V (LM3464A)

individual current regulator channels and works in

conjunction with external N-channel MOSFETs and

• Dynamic Headroom Control Ensures Maximum

sense resistors to give accurate driving current for

Efficiency

every LED string. Additionally, the Dynamic

• 4 Output Channels With Individual Current

Headroom Control (DHC) output can be interfaced to

Regulation

the external power supply to adjust the LED supply

• High Channel to Channel Accuracy

voltage to the lowest level that is adequate to

maintain all the string currents in regulation, yielding

• Digital PWM/Analog Dimming Control Interface

the optimal overall efficiency.

• Resistor Programmable Dimming Frequency

Digital PWM or analog voltage signals can be used to

and Minimum Duty Cycle (Analog Dimming

control the duty cycle of the all the channels. When

Mode)

analog control is used, the dimming frequency can be

• Direct Interface to Thermal Sensor

programmed via an external capacitor. A minimum

• Fault Detection

duty cycle control is provided in the conditions that

the analog dimming is configured as thermal

• Over Temperature Protection

feedback.

• Thermal Shutdown

Protection features include VIN under-voltage lock-

• Under Voltage Lockout

out, LED open/short circuit and over-temperature fault

• Thermal Enhanced TSSOP-28 Package

signaling to the system controller.

APPLICATIONS

• Streetlights

• Solid State Lighting Solutions

Typical Application

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2All trademarks are the property of their respective owners.

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.

Summary of content (31 pages)

PAGE 1
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 DESCRIPTION • The LM3464/64A is a 4-channel high voltage current regulator that provides a simple solution for LED lighting applications.
PAGE 2
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.com Connection Diagram Figure 1. Top View 28-Lead TSSOP-28 Package Number PWP PIN DESCRIPTIONS 2 Pin Name Description Application Information 1 SYNC Synchronization signal output for cascade operation (Master-Slave configuration) Connect this pin to the DIM pin of other LM3464/64A to enable cascade operation (multiple device). This pin should leave open for single device operation.
PAGE 3
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 PIN DESCRIPTIONS (continued) Pin Name Description Application Information 19 DR1 Channel 1 drain sense input This pin senses the drain voltage of the external MOSFET of channel 1 to facilitate DHC operation and fault detection. 20 SE4 Channel 4 sense input Connect to an external sense resistor to define the Channel 4 LED current.
PAGE 4
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.com These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. Absolute Maximum Ratings (LM3464/LM3464A) (1) (2) VIN to GND -0.3V to 100V DR1, DR2, DR3, DR4 to GND -0.3V to 100V EN to GND -0.3V to 5.5V All other inputs to GND ESD Rating -0.
PAGE 5
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 Electrical Characteristics (LM3464/LM3464A) (continued) Specification with standard type are for TA = TJ = +25°C only; limits in boldface type apply over the full Operating Junction Temperature (TJ) range. Minimum and Maximum are specified through test, design or statistical correlation. Typical values represent the most likely parametric norm at TJ = +25°C, and are provided for reference purposes only.
PAGE 6
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics All curves taken at VIN = 48V with configuration in typical application for driving twelve power LEDs with four output channels active and output current per channel = 350 mA. TA = 25°C, unless otherwise specified. 6 Channel 1 Current Sense Voltage (VSE1) Effifciency (%) Figure 2. Figure 3. Thermal_Cap Pin Output Current VCC Variation (%) Figure 4. Figure 5.
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LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 Typical Performance Characteristics (continued) All curves taken at VIN = 48V with configuration in typical application for driving twelve power LEDs with four output channels active and output current per channel = 350 mA. TA = 25°C, unless otherwise specified. Startup Waveforms PWM Dimming (DIM pin) Figure 8. Figure 9. PWM Dimming Delay Time (VDIM) rising) PWM Dimming Delay Time (VDIM) falling) Figure 10. Figure 11.
PAGE 8
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.
PAGE 9
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 Figure 14.
PAGE 10
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.com OVERVIEW The LM3464/64A is a four channel linear current regulator designed for LED lighting systems with wide input voltage range, high speed PWM and thermal foldback dimming control interface. The LM3464/64A incorporates a Dynamic Headroom Control (DHC) technology which maximizes overall efficiency of the lighting system by adjusting the output voltage of the primary power source dynamically.
PAGE 11
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 System Operation In order to provide failure protection to the LEDs, the rail voltage is pulled up by the LM3464/64A from a relatively low voltage level at system startup until the rail voltage reaches certain preset level. Figure 16 shows the change of the rail voltage of the LM3464/64A LED lighting system upon the primary power source is powered.
PAGE 12
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.com APPLICATION INFORMATION SETTING (VRAIL(nom)) The nominal rail voltage VRAIL(nom) is the nominal output voltage of the primary power supply (AC/DC) prior to DHC begins.
PAGE 13
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 VVDHC is the voltage at the VDHC pin. This voltage decides the headroom voltage for the LM3464/64A driver stage and equals to the minimum VDRx among the drain voltages of the MOSFETs under steady state. The VDHC pin is internally biased to 0.9V which also set the default voltage headroom to 0.9V. In applications that the output of the AC/DC converter contains more than 0.
PAGE 14
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.com Figure 18. Linear LED Current Regulator The driving currents of the LED strings are defined by the values of RISNS1 to RISNS4 individually.
PAGE 15
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 Figure 20. Simplified Circuit of the Frequency Response Setting Mechanism The transconductance amplifier serves as a voltage to current converter that charges CDHC with a current proportional to the difference in voltage between the DRx and VDHC pins.
PAGE 16
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 VThermal www.ti.com VCC 3.25V ILED (AVG) 100% 0.4V 0V Approximately 0.5% (Limited by tTHM_MIN) Temperature Thermal foldback begin Figure 21. Average LED Current Reduces According to VThermal The dimming frequency is defined by a sawtooth waveform that generated by charging and discharging the capacitor CTHM which connects across the Thermal_Cap pin and GND. The LM3464/64A charges the CTHM up to 3.
PAGE 17
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 If the voltage at the Thermal pin is driven to exceed 3.25V, all output channels will be enabled with 100% thermal dimming duty cycle. If the Thermal pin voltage is set below 0.4V, all output channels will be disabled with 0% thermal dimming duty cycle. The dimming frequency and duty cycle with thermal foldback control are governed by the following equations: fThermal-foldback = 50 PA (3.25 - 0.
PAGE 18
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.com ILED(AVG) = DPWM x ILED (20) PWM DIMMING CONTROL WITH THERMAL FOLDBACK The PWM dimming control can coexist with thermal foldback by applying PWM dimming control signal and thermal control signal to the DIM and Thermal pins concurrently. Normally, the dimming frequency for thermal foldback control should be much higher than the frequency of the PWM dimming control signal.
PAGE 19
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 OPEN CIRCUIT OF LED STRINGS Detection of LED open circuit is achieved by detecting the voltages of the SEx pin and the internal gate control signal being fed to the internal MOSFET gate driver. When a LED string is open circuit, the VSEx pin is pulled down to below 30mV by the current sensing resistor.
PAGE 20
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.com CONNECTION TO LED ARRAYS When LEDs are connected to the LM3464/64A driver stage through long cables, the parasitic components of the cable harness and external MOSFETs may resonant and eventually lead to unstable system operation. In applications that the cables between the LM3464/64A driver circuit and LED light engine are longer than 1 meter, a 4.7kΩ resistor should be added across the GDx pins to GND as shown in Figure 25. Figure 25.
PAGE 21
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 Figure 26. Additional Voltage Clamping Circuits for VRAIL(peak) > 80V/95V (LM3464/64A) APPLICATIONS WITH HIGH RAIL VOLTAGE The normal operation voltage of the LM3464 and LM3464A are rated to 80V and 95V respectively, applying voltage over the operation voltage limit to the LM3464/64A can damage the device permanently.
PAGE 22
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.com In Figure 26, Z1, Z2, Z3, Z4 and ZIN are zener diodes for clamping the DRx pin voltage and input voltage (VIN pin) of the LM3464/64A. The reverse voltage of the zener diodes must be below 80V for LM3464 and 95V for LM3464A. The resistors RDR1, RDR2, RDR3, RDR4 and RIN are resistors for absorbing the voltage difference between the clamping voltage of the zener diodes and the rail voltage.
PAGE 23
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 The value of RIN is governed by the following equations: (27) Maximum value of RIN: (28) Minimum value of RIN: (29) So the value of RIN must be in the range: (30) To minimize power dissipations on both the ZIN and RIN, a standard 9.31kΩ resistor can be selected for the RIN. Then the maximum power dissipation on RIN is: (31) Thus, a standard 9.38kΩ resistor with 2512 package (1W) and 1% tolerance can be used.
PAGE 24
LM3464, LM3464A SNVS652F – APRIL 2010 – REVISED MAY 2013 www.ti.com Additional Application Circuit Figure 27.
PAGE 25
LM3464, LM3464A www.ti.com SNVS652F – APRIL 2010 – REVISED MAY 2013 REVISION HISTORY Changes from Revision E (May 2013) to Revision F • Page Changed layout of National Data Sheet to TI format ..........................................................................................................
PAGE 26
PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 28-Aug-2013 continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
PAGE 28
PACKAGE MATERIALS INFORMATION www.ti.com 8-May-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) LM3464AMHX/NOPB HTSSOP PWP 28 2500 330.0 16.4 LM3464MHX/NOPB HTSSOP PWP 28 2500 330.0 16.4 Pack Materials-Page 1 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 6.8 10.2 1.6 8.0 16.0 Q1 6.8 10.2 1.6 8.0 16.
PAGE 29
PACKAGE MATERIALS INFORMATION www.ti.com 8-May-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM3464AMHX/NOPB HTSSOP PWP 28 2500 367.0 367.0 35.0 LM3464MHX/NOPB HTSSOP PWP 28 2500 367.0 367.0 35.
PAGE 30
MECHANICAL DATA PWP0028A MXA28A (Rev D) www.ti.
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