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LM3445 TRIAC Dimmable Offline LED Driver Datasheet

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LM3445 TRIAC Dimmable Offline LED Driver Datasheet Product Sample & Technical Tools & Support & Reference Folder Buy Documents Software Community Design LM3445 SNVS570M –JANUARY 2009–REVISED NOVEMBER 2015 LM3445 TRIAC Dimmable Offline LED Driver 1 Features 3 Description The LM3445 is an adaptive constant off-time AC/DC 1• TRIAC Dim Decoder Circuit for LED Dimming buck (step-down) constant current controller designed • Application Voltage Range 80 VAC to 277 VAC to be compatible with TRIAC dimmers. The LM3445 • Capable of Controlling LED Currents Greater provides a constant current for illuminating high Than 1 A power LEDs and includes a TRIAC dim decoder. The • Adjustable Switching Frequency dim decoder allows wide range LED dimming using standard TRIAC dimmers. The high frequency • Low Quiescent Current capable architecture allows the use of small external • Adaptive Programmable Off-Time Allows for passive components. The LM3445 includes a bleeder Constant Ripple Current circuit to ensure proper TRIAC operation by allowing • Thermal Shutdown current flow while the line voltage is low to enable proper firing of the TRIAC. A passive PFC circuit • No 120-Hz Flicker ensures good power factor by drawing current directly • Low Profile 10-Pin VSSOP Package or 14-Pin from the line for most of the cycle, and provides a SOIC constant positive voltage to the buck regulator. • Patented Drive Architecture Additional features include thermal shutdown, current limit and VCC under-voltage lockout. 2 Applications Device Information(1) • Retro Fit TRIAC Dimming PART NUMBER PACKAGE BODY SIZE (NOM) • Solid State Lighting VSSOP (10) 3.00 mm × 3.00 mm LM3445 • Industrial and Commercial Lighting SOIC (14) 3.91 mm × 8.65 mm • Residential Lighting (1) For all available packages, see the orderable addendum at the end of the data sheet. Typical LM3445 LED Driver Application Circuit Efficiency vs Line Voltage V+ D3 VBUCK 95.0 + C7 D9 14 Series connected LEDs BR1 C10 D8 + VLED R2 D4 C9 C12 - R4 90.0 TRIAC Q1 V DIMMER D2 LED- VAC D1 R5 D10 85.0 C5 Q3 L2 10 Series connected LEDs LM3445MM EFFICIENCY (%) 80.0 1 ASNS BLDR 10 U1 R1 ICOLL 2 FLTR1 VCC 9 75.0 80 90 100 110 120 130 140 C3 3 DIM 8 Q2 GATE LINE VOLTAGE (VAC) 4 COFF ISNS 7 R3 5FLTR2 GND 6 C4 C11 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. LM3445 SNVS570M –JANUARY 2009–REVISED NOVEMBER 2015 www.ti.com Table of Contents 1 Features .................................................................. 1 7.3 Feature Description................................................... 8 2 Applications ........................................................... 1 7.4 Device Functional Modes........................................ 20 3 Description ............................................................. 1 8 Application and Implementation ........................ 21 4 Revision History..................................................... 2 8.1 Application Information............................................ 21 5 Pin Configuration and Functions ......................... 3 8.2 Typical Application ................................................. 29 6 Specifications......................................................... 4 9 Power Supply Recommendations...................... 33 6.1 Absolute Maximum Ratings ..................................... 4 10 Layout................................................................... 33 6.2 ESD Ratings.............................................................. 4 10.1 Layout Guidelines ................................................. 33 6.3 Recommended Operating Conditions....................... 4 10.2 Layout Example .................................................... 33 6.4 Thermal Information.................................................. 4 11 Device and Documentation Support ................. 34 6.5 Electrical Characteristics........................................... 5 11.1 Community Resources.......................................... 34 6.6 Typical Characteristics.............................................. 6 11.2 Trademarks ........................................................... 34 7 Detailed Description .............................................. 8 11.3 Electrostatic Discharge Caution............................ 34 7.1 Overview ................................................................... 8 11.4 Glossary ................................................................ 34 7.2 Functional Block Diagram ......................................... 8 12 Mechanical, Packaging, and Orderable Information ........................................................... 34 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision L (May 2013) to Revision M Page • Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section. ................................................................................................. 1 • Removed maximum lead temperature (soldering). ............................................................................................................... 4 Changes from Revision K (May 2013) to Revision L Page • Changed layout of National Data Sheet to TI format ........................................................................................................... 32 2 Submit Documentation Feedback Copyright © 2009–2015, Texas Instruments Incorporated Product Folder Links: LM3445 LM3445 www.ti.com SNVS570M –JANUARY 2009–REVISED NOVEMBER 2015 5 Pin Configuration and Functions DGS Package 10-Pin VSSOP D Package Top View 14-Pin SOIC Top View ASNS 1 10 BLDR COFF 1 14 DIM FLTR1 2 9 VCC N/C 2 13 FLTR1 DIM 3 8 GATE FLTR2 3 12 ASNS COFF 4 7 ISNS GND 4 11 N/C FLTR25 6 GND N/C5 10 BLDR N/C 6 9 VCC ISNS 7 8 GATE Pin Functions PIN I/O DESCRIPTION NAME SOIC VSSOP PWM output of the TRIAC dim decoder circuit. Outputs a 0 to 4-V PWM signal ASNS 12 1 O with a duty cycle proportional to the TRIAC dimmer on-time. Bleeder pin. Provides the input signal to the angle detect circuitry as well as a BLDR 10 10 I current path through a switched 230-Ω resistor to ensure proper firing of the TRIAC dimmer. OFF time setting pin. A user set current and capacitor connected from the COFF 1 4 I output to this pin sets the constant OFF time of the switching controller. Input/output dual function dim pin. This pin can be driven with an external PWM signal to dim the LEDs. It may also be used as an output signal and connected DIM 14 3 I/O to the DIM pin of other LM3445s or other LED drivers to dim multiple LED circuits simultaneously. First filter input. The 120-Hz PWM signal from ASNS is filtered to a DC signal and compared to a 1 to 3 V, 5.85-kHz ramp to generate a higher frequency FLTR1 13 2 I PWM signal with a duty cycle proportional to the TRIAC dimmer firing angle. Pull above 4.9-V (typical) to tri-state DIM. Second filter input. A capacitor tied to this pin filters the PWM dimming signal FLTR2 3 5 I to supply a DC voltage to control the LED current. Could also be used as an analog dimming input. Power MOSFET driver pin. This output provides the gate drive for the power GATE 8 8 O switching MOSFET of the buck controller. GND 4 6 — Circuit ground connection LED current sense pin. Connect a resistor from main switching MOSFET ISNS 7 7 I source, ISNS to GND to set the maximum LED current. N/C 2, 5, 6, 11 — — No Connect Input voltage pin. This pin provides the power for the internal control circuitry VCC 9 9 O and gate driver. Copyright © 2009–2015, Texas Instruments Incorporated Submit Documentation Feedback 3 Product Folder Links: LM3445 LM3445 SNVS570M –JANUARY 2009–REVISED NOVEMBER 2015 www.ti.com 6 Specifications 6.1 Absolute Maximum Ratings See(1) (2)(3) MIN MAX UNIT BLDR to GND –0.3 17 V VCC, GATE, FLTR1 to GND –0.3 14 V ISNS to GND –0.3 2.5 V ASNS, DIM, FLTR2, COFF to GND –0.3 7 V COFF Input Current 100 mA Continuous Power Dissipation(4) Internally Limited Junction Temperature (TJ-MAX) 150 °C Storage Temperature –65 150 °C (1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability (2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and specifications. (3) All voltages are with respect to the potential at the GND pin, unless otherwise specified. (4) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ = 165°C (typ.) and disengages at +TJ = 145°C (typ). 6.2 ESD Ratings VALUE UNIT Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1)(2) ±2000 V(ESD) Electrostatic discharge Charged-device model (CDM), per JEDEC specification JESD22- V ±1000 C101(3) (1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. (2) Human Body Model, applicable std. JESD22-A114-C. (3) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard
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