Product Folder Sample & Buy Support & Community Tools & Software Technical Documents Reference Design LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 LM3492/-Q1 Two-Channel Individual Dimmable LED Driver With Boost Converter and Fast Current Regulator 1 1 Features * * * Boost Converter: - LM3492-Q1 is an Automotive Grade Product That is AEC Q100 Grade 1 Qualified - Very Wide Input Voltage Ranged From 4.5 V to 65 V - Programmable Soft Start - No Loop Compensation Required - Stable With Ceramic and Other Low ESR Capacitors With No Audible Noise - Nearly Constant Switching Frequency Programmable From 200 kHz to 1 MHz Current Regulators: - Programmable LED Current from 50 mA to 200 mA - 1000:1 Contrast Ratio at a Dimming Frequency of More Than 3 kHz, Minimum LED Current Pulse Width is 300 ns - Two Individual Dimmable LED Strings up to 65 V, Total 15 W (Typically 28 LEDs at 150 mA) - Dynamic Headroom Control Maximizes Efficiency - Over-Power Protection - 3% Current Accuracy Supervisory Functions: - Precision Enable - COMM I/O Pin for Diagnostic and Commands - Thermal Shutdown Protection - Thermally Enhanced 20-Pin HTSSOP package 2 Applications * * Ultra-High Contrast Ratio 6.5"-10" LCD Display Backlight up to 28 LEDs Automotive or Marine GPS Displays 3 Description The LM3492/-Q1 integrates a boost converter and a two-channel current regulator to implement a high efficient and cost effective LED driver for driving two individually dimmable LED strings with a maximum power of 15 W and an output voltage of up to 65 V. The boost converter employs a proprietary ProjectedOn-Time control method to give a fast transient response with no compensation required, and a nearly constant switching frequency programmable from 200 kHz to 1 MHz. The application circuit is stable with ceramic capacitors and produces no audible noise on dimming. The programmable peak current limit and soft-start features reduce current surges at start-up, and an integrated 190 m, 3.9-A N-Channel MOSFET switch minimizes the solution size. Device Information(1) PART NUMBER LM3492 LM3492-Q1 PACKAGE HTSSOP (20) BODY SIZE (NOM) 7.80 mm x 4.40 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Typical Application Copyright (c) 2016, Texas Instruments Incorporated 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. LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com Table of Contents 1 2 3 4 5 6 7 8 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Description (continued)......................................... Pin Configuration and Functions ......................... Specifications......................................................... 1 1 1 2 3 4 5 7.1 7.2 7.3 7.4 7.5 7.6 5 5 5 5 6 8 Absolute Maximum Ratings ...................................... ESD Ratings.............................................................. Recommended Operating Conditions....................... Thermal Information .................................................. Electrical Characteristics........................................... Typical Characteristics .............................................. Detailed Description ............................................ 11 8.1 8.2 8.3 8.4 Overview ................................................................. Functional Block Diagram ....................................... Feature Description................................................. Device Functional Modes........................................ 11 12 12 18 8.5 Programming........................................................... 18 9 Application and Implementation ........................ 20 9.1 Application Information............................................ 20 9.2 Typical Application ................................................. 20 10 Power Supply Recommendations ..................... 23 11 Layout................................................................... 23 11.1 Layout Guidelines ................................................. 23 11.2 Layout Example .................................................... 23 12 Device and Documentation Support ................. 24 12.1 12.2 12.3 12.4 12.5 12.6 12.7 Documentation Support ........................................ Related Links ........................................................ Receiving Notification of Documentation Updates Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 24 24 24 24 24 24 24 13 Mechanical, Packaging, and Orderable Information ........................................................... 25 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision C (May 2013) to Revision D Page * Added Added ESD Ratings table, Thermal Information 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 * Changed RJA value from 32.7 to 36.5 in the Thermal Information table ............................................................................... 5 Changes from Revision B (May 2013) to Revision C * 2 Page Changed layout of National Data Sheet to TI format ........................................................................................................... 20 Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 5 Description (continued) The fast slew rate current regulator allows high frequency and narrow pulse width dimming signals to achieve a very high contrast ratio of 1000:1 at a dimming frequency of more than 3 kHz. The LED current is programmable from 50 mA to 200 mA by a single resistor. To maximize the efficiency, Dynamic Headroom Control (DHC) automatically adjusts the output voltage to a minimum. DHC also facilitates a single BOM for different number of LED in a string, which is required for backlight panels of different size, thereby reducing overall development time and cost. The LM3492/-Q1 comes with a versatile COMM pin which serves as a bidirectional I/O pin interfacing with an external MCU for the following functions: power-good, overtemperature, IOUT overvoltage and undervoltage indications, switching frequency tuning, and channel 1 disabling. Other supervisory functions of the LM3492/-Q1 include precise enable, VCC undervoltage lockout, current regulator over-power protection, and thermal shutdown protection. The LM3492/-Q1 is available in the thermally enhanced 20-pin HTSSOP package. Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 3 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com 6 Pin Configuration and Functions PWP PowerPADTM Package 20-Pin HTSSOP Top View Pin Functions PIN NO. NAME I/O DESCRIPTION APPLICATION INFORMATION 1 EN I Enable Internally pullup. Connect to a voltage higher than 1.63 V to provide precision enable for the device. 2 VIN I Input Supply Voltage Supply pin to the device. Input range is 4.5 V to 65 V. SW I Switch Node Internally connected to the drain of the integrated MOSFET. 5 VOUT I Output Voltage Sense Sense the output voltage for nearly constant switching frequency control. 6 RT I Frequency Control An external resistor from the VOUT pin to this pin sets the switching frequency. 7 FB I Output Voltage Feedback The output voltage is connected to this pin through a feedback resistor divider for output voltage regulation. The voltage of this pin is from 1.05 V to 2.5 V. 8 GND G Analog Ground Signal ground 3 4 9 IOUT2 I Current Regulator Input Input of the current regulator of channel 2. The regulated current is programmable of Channel 2 (refer to the IREF pin). 10 IOUT1 I Current Regulator Input Input of the current regulator of channel 1. The regulated current is programmable of Channel 1 (refer to the IREF pin). 11 CDHC I Dynamic Headroom Control An external capacitor connected to this pin sets the DHC sensitivity. At start-up, a 120-A internal current source charges an external capacitor to provide a soft-start function. 12 IREF I Current Setting of the Current Regulator An external resistor connected from this pin to ground programs the regulated current of the current regulator of channels 1 and 2. 13 COMM I/O Bidirectional Logic Communication This pin is open drain for various indications (power-good, overtemperature, IOUT overvoltage and undervoltage) and command sending (switching frequency tuning and channel 1 disabling). 14 LGND G Ground of the Current Regulator Current regulator ground. Must be connected to the GND pin for normal operation. The LGND and GND pins are not internally connected. 15 DIM1/CLK I/O Dimming Control of Channel 1 Control the ON/OFF of the current regulator of channel 1. This pin is internally pulled low by a 5-A current. This pin also serves as a clock signal for latching input/output data of the COMM pin. 16 DIM2 I Dimming Control of Channel 2 Control the ON/OFF of the current regulator of channel 2. This pin is internally pulled low by a 5-A current. PGND G Power Ground Integrated MOSFET ground. Must be connected to the GND pin for normal operation. The PGND and GND pins are not internally connected. 19 VCC O LDO Regulator Output Nominally regulated to 5.5 V. Connect a capacitor of larger than 0.47 F between the VCC and GND pins. 20 ILIM I Peak Current Limit Adjust Connect an external resistor from the ILIM pin to the VCC pin reduces peak current limit. Connect the ILIM pin to the ground to obtain the maximum current limit. DAP DAP -- Exposed Pad Thermal connection pad. Connect to a ground plane. 17 18 4 Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 7 Specifications 7.1 Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted) (1) Input voltage MIN MAX VIN, RT, VOUT to GND -0.3 67 SW to GND -0.3 UNIT 67 V -2 (<100 ns) SW to GND (Transient) ILIM to GND -0.3 0.3 FB to GND -0.3 5 COMM, DIM1, DIM2, to GND -0.3 6 Junction temperature, TJ 150 150 C Storage temperature, Tstg -65 150 C Output voltage (1) V 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. 7.2 ESD Ratings VALUE V(ESD) (1) (2) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) UNIT 2000 Charged-device model (CDM), per JEDEC specification JESD22-C101 (2) V 750 JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. 7.3 Recommended Operating Conditions over operating free-air temperature range (unless otherwise noted) MIN MAX Supply voltage, VIN 4.5 65 UNIT V Operation temperature, TA -40 125 C 7.4 Thermal Information LM3492, LM3492-Q1 THERMAL METRIC (1) PWP (HTSSOP) UNIT 20 PINS RJA Junction-to-ambient thermal resistance 36.5 C/W RJC(top) Junction-to-case (top) thermal resistance 20.8 C/W RJB Junction-to-board thermal resistance 17.5 C/W JT Junction-to-top characterization parameter 0.5 C/W JB Junction-to-board characterization parameter 17.4 C/W RJC(bot) Junction-to-case (bottom) thermal resistance 2 C/W (1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report. Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 5 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com 7.5 Electrical Characteristics over operating free-air temperature range, VIN = 12 V (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT CVCC = 0.47 F, no load 4.7 5.5 6.3 V IVCC = 2 mA 4.7 5.5 6.3 V 3.56 3.78 4 V START-UP REGULATOR (VCC PIN) VVCC Output voltage VCC_UVLO VCC pin undervoltage lockout threshold (UVLO) VVCC increasing, TA = TJ = 25C VCC_UVLO-HYS VCC pin UVLO hysteresis VVCC decreasing 310 IIN IIN operating current No switching, VFB = 0 V 3.6 5.2 mA IIN-SD IIN operating current, device shutdown VEN = 0 V 30 95 A (1) mV IVCC VCC pin current limit VVCC = 0 V 18 30 VCC-VOUT VCC pin output voltage when supplied by VOUT VIN = Open, IVCC = 1 mA, VOUT = 18 V, TA = TJ = 25C mA 3.5 4.1 4.7 V VEN EN pin input threshold VEN rising 1.55 1.63 1.71 V VEN-HYS EN pin threshold hysteresis VEN falling 194 mV IEN-SHUT Enable pullup current at shutdown VEN = 0 V 2 A IEN-OPER Enable pullup current during operation VEN = 2 V 40 A ENABLE INPUT CURRENT REGULATOR VIREF 4.5 V VIN 65 V IREF pin voltage VDHC50 VDHC100 1.256 1.281 0.16 0.225 0.29 IOUT = 100 mA, RIREF = 12.5 k 0.38 0.48 0.58 VDHC200 IOUT = 200 mA, RIREF = 6.25 k 0.81 0.99 1.17 IOUT50 VIOUT = VDHC50, RIREF = 25 k, TA = TJ = 25C 47.5 50 52.5 VIOUT = VDHC50, RIREF = 25 k IOUT100 VIOUT under DHC 1.231 IOUT = 50 mA, RIREF = 25 k Current output under DHC IOUT200 IOUTOFF Leakage at maximum work voltage VIOUT50-MIN VIOUT100-MIN Minimum work voltage VIOUT200-MIN VDIM-HIGH DIM voltage HIGH VDIM-LOW DIM voltage LOW 46.5 50 53.5 VIOUT = VDHC100, RIREF = 12.5 k, TA = TJ = 25C 97 100 103 VIOUT = VDHC100, RIREF = 12.5 k 96 100 104 VIOUT = VDHC200, RIREF = 6.25 k, TA = TJ = 25C 194 200 206 VIOUT = VDHC200, RIREF = 6.25 k 192 200 208 VDIM = 0, VIOUT = 65 V, TA = TJ = 25C 5 IOUT = 50 mA, RIREF = 25 k, IOUT = 0.98 x IOUT50, TA = TJ = 25C 0.1 0.15 IOUT = 100 mA, RIREF = 12.5 k, IOUT = 0.98 x IOUT100, TA = TJ = 25C 0.2 0.35 IOUT = 200 mA, RIREF = 6.25 k, IOUT = 0.98 x IOUT200, TA = TJ = 25C 0.4 0.65 1.17 V V mA A V V 0.7 V BOOST CONVERTER ICDHC-SRC CDHC pin source current VCDHC = 1.6 V, VFB = 3 V, VIOUT = 0 V, DIM = High 60 A ICDHC-SINK CDHC pin sink current VCDHC = 1.6 V, VFB = 3 V, VIOUT = 3 V, DIM = High 56 A (1) 6 The VCC pin provides self bias for the internal gate drive and control circuits. Device thermal limitations limit external loading. Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 Electrical Characteristics (continued) over operating free-air temperature range, VIN = 12 V (unless otherwise noted) PARAMETER TEST CONDITIONS MIN DIM = Low, VCDHC = 2.6 V, TA = TJ = 25C TYP MAX 5 46 nA 3.9 4.5 A ICDHC-LEAKAGE CDHC pin leakage current ICL-MAX Integrated MOSFET peak current limit threshold ICL-HALF Half integrated MOSFET peak current limit threshold RILIM = 11 k 2 RDS(on) Integrated MOSFET On-resistance ISW = 500 mA 0.19 VFBTH-PWRGD Power-Good FB pin threshold IFB Feedback pin input current 3.3 VIN = 12 V, VOUT = 65 V, RRT = 300 k tON ON timer pulse width A 0.43 1 A 2.25 VFB = 3 V, TA = TJ = 25C UNIT V 1460 VIN = 24 V, VOUT = 32.5 V, RRT = 300 k 800 VIN = 12 V, VOUT = 65 V, RRT = 100 k 550 VIN = 24 V, VOUT = 32.5 V, RRT = 100 k 350 ns tON(min)ILIM ON timer minimum pulse width at current limit 145 tOFF OFF timer pulse width 145 350 ns 6.7 7.8 V ns COMM PIN VIOUT-OV IOUT pin overvoltage threshold COMM goes LOW during VIOUT rising, other VIOUT = 1.2 V VCOMM-LOW COMM pin at LOW 5 mA into COMM ILEAK-FAULT COMM pin open leakage VCOMM = 5 V 5.6 0.7 V 5 A THERMAL PROTECTION TOTM Overtemperature indication TJ rising 135 C TOTM-HYS Overtemperature indication hysteresis TJ falling 15 C TSD Thermal shutdown temperature TJ rising 165 C TSD-HYS Thermal shutdown temperature hysteresis TJ falling 20 C Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 7 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com 7.6 Typical Characteristics Unless otherwise specified the following conditions apply: TJ = 25C, VIN = 12 V with configuration in typical application circuit for ILED = 200 mA shown in this data sheet. 8 Figure 1. Quiescent Current, IIN vs VIN Figure 2. VCC vs IVCC Figure 3. VCC vs VIN Figure 4. Switching Frequency, fSW vs VIN Figure 5. ILED Regulation vs Temperature Figure 6. RDS(on) vs Temperature Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 Typical Characteristics (continued) Unless otherwise specified the following conditions apply: TJ = 25C, VIN = 12 V with configuration in typical application circuit for ILED = 200 mA shown in this data sheet. Figure 7. Efficiency vs VIN (ILED = 0.2 A) Figure 8. ILED Regulation vs VIN (ILED = 0.2 A) Figure 9. Power Up (ILED = 0.2 A) Figure 10. Enable Transient (ILED = 0.2 A) Figure 11. Steady-State Operation (ILED = 0.2 A) Figure 12. LED 50% Dimming (ILED = 0.2 A, Dimming Frequency = 200 Hz) Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 9 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com Typical Characteristics (continued) Unless otherwise specified the following conditions apply: TJ = 25C, VIN = 12 V with configuration in typical application circuit for ILED = 200 mA shown in this data sheet. Figure 13. 1000:1 LED Dimming (ILED = 0.2 A, Dimming Frequency = 200 Hz) 10 Submit Documentation Feedback Figure 14. 300-ns LED Dimming Pulse Width (ILED = 0.2 A, Dimming frequency = 3.33 kHz) Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 8 Detailed Description 8.1 Overview The LM3492/-Q1 integrates a boost converter and a two-channel current regulator to implement a high efficient and cost effective LED driver for driving two individually dimmable LED strings with a maximum power of 15 W and an output voltage of up to 65 V. The boost converter provides power for the LED strings, and the current regulator controls the dimming of the LED strings individually. The LM3492/-Q1 integrates an N-channel MOSFET switch and a two-channel current regulator to minimize the component count and solution size. The boost converter of the LM3492/-Q1 employs a Projected On-Time (POT) control method to determine the on-time of the MOSFET with respect to the input and output voltages and an external resistor RRT. During the onperiod, the boost inductor is charged up, and the output capacitor is discharged to provide power to the output. A cycle-by-cycle current limit (which is 3.9 A typically and programmable by an external resistor) is imposed on the MOSFET for protection. After the on-period, the MOSFET is turned off such that the boost inductor is discharged. The next on-period is started when the voltage of the FB pin is dropped below a threshold which is determined by Dynamic Headroom Control (DHC) and is ranged from 1.05 V to 2.5 V (DHC affects the threshold only when the DIM1 and/or DIM2 pins are high). The boost converter under POT control can maintain the switching frequency nearly constant so that the switching frequency depends on only RRT (Figure 15). Also, POT control requires no compensation circuit and gives a fast transient response of the output voltage. Figure 15. Switching Frequency The two-channel current regulator of the LM3492/-Q1 is fast response so that it can allow very high contrast ratio (1000:1 at 3-kHz LED dimming frequency, minimum pulse width of the dimming signal is 300 ns). The two channels are dimmable individually. Channel 1 of the current regulator can be disabled by a digital command send through the COMM pin. In this case, the DIM1 pin can serve only as a clock signal for the data flow of the COMM pin. The power dissipated by the current regulator is adaptively minimized by Dynamic Headroom Control to maximize efficiency. The LM3492/-Q1 can be applied in numerous applications like automotive LCD backlight panels. It can operate efficiently for inputs as high as 65 V. Diagnostic functions including power good indication, overtemperature indication, IOUT overvoltage and undervoltage indications facilitate the interface of the LM3492/-Q1 application circuit with external microprocessors (MCUs). The LM3492/-Q1 will not latch off and continue to operate in the presence of the indications. Other useful features include thermal shutdown, VCC undervoltage lockout, and precision enable. The LM3492/-Q1 is available in the thermally enhanced HTSSOP package. Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 11 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com 8.2 Functional Block Diagram Copyright (c) 2016, Texas Instruments Incorporated 8.3 Feature Description 8.3.1 Switching Frequency The boost converter of the LM3492/-Q1 device employs a projected-on-time (POT) control method to determine the on-time period of the MOSFET with respect to the input and output voltages and an external resistor RRT. During the on-time period, the boost inductor charges up, and the output capacitor discharges to provide power to the output. A cycle-by-cycle current limit (which is 3.9 A typically and programmable by an external resistor) protects the MOSFET. After the on-time period, the MOSFET turns off and boost inductor discharges. The next on-time period starts when the voltage of the FB pin drops below a threshold which is determined by dynamic headroom control (DHC) and operates from 1.05 V to 2 V. DHC affects the threshold when either the DIM1 pin is high or the DIM2 pin is high. During POT control operation, the boost converter maintains switching at a nearly constant frequency. During most operating conditions, the switching frequency depends on mainly the value of RRT (Figure 16) but may see some variation with changes in input or output voltage. Also, POT control operation requires no compensation circuit and offers fast transient response of the output voltage. Applications that require very wide input voltage or very wide output voltage ranges may see some variation in the switching frequency as shown in Figure 17 and Figure 18. 12 Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 Feature Description (continued) 600 950 Switching Frequency (kHz) Switching Frequency (kHz) 560 850 750 650 550 450 350 250 520 480 440 400 360 320 280 240 150 100 200 300 ILED = 150 mA 400 500 RRT (k:) 600 700 200 800 6 8 10 12 14 16 18 Input Voltage (V) D001 VOUT = 30 V VVIN = 12 V ILED = 150 mA Figure 16. Switching Frequency vs RT Resistance VOUT = 30 V 20 22 24 26 D001 RRT = 274 k Figure 17. Switching Frequency vs Input Voltage 600 Switching Frequency (kHz) 570 540 510 480 450 420 390 360 330 300 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Output Voltage (V) D001 ILED = 150 mA RRT = 274 k VVIN = 12 V Figure 18. Switching Frequency vs Output Voltage 8.3.2 LDO Regulator The LM3492/-Q1 device offers an integrated, 5.5-V, LDO regulator. For stability, connect an external capacitor CVCC of more than 0.47-F between the VCC and GND pins. The current limit of the LDO is typically 30 mA. The LDO regulator can be used to pullup the open-drain COMM pin with an external resistor, and sources current to the ILIM pin to adjust the current limit of the integrated MOSFET. When the voltage on the VCC pin (VCC) is higher than the undervoltage lockout (UVLO) threshold of 3.78 V, the device becomes enabled and the CDHC pin sources a current to charge up an external capacitor (CCDHC) to provide a soft-start function. 8.3.3 Enable and Disable To enable the LM3492/-Q1 device, the voltage on the EN pin (VEN) must be higher than an enable threshold of typically 1.63 V. If the voltage on the EN pin (VEN) is lower than 1.43 V, the device shuts down. In this case, the LDO regulator turns off and the CDHC pin becomes internally grounded. The EN pin internally pulls up. After enable, a 40-A current source pulls up the EN pin. If the EN pin is connected to low such that the device is shut down, the pullup current is reduced to 2 A. These advantages allow the device to effectively avoid false disabling by noise during operation, and minimize power consumption during shutdown. The enable threshold is so precise that it can support a UVLO function for the input voltage as shown in Figure 19. The input voltage can be connected to the EN pin through a resistor divider consisting of REN1 and REN2. This circuitry ensures that the device operates after the input voltage reaches a minimum require value VIN(EN), as shown in Equation 1. Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 13 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com Feature Description (continued) VIN(EN) = 1.63 V(1 + REN1/ REN2) (1) To maintain the VEN level below the absolute maximum specification, place a Zener diode (DEN) between the EN pin and GND pins. VVIN VIN REN1 EN GND REN2 DEN Figure 19. Input Voltage UVLO Implemented by Precision Enable After the EN pin is pulled low, the device performs the following functions: * resets IOUT overvoltage and undervoltage indications and the corresponding COMM bit pattern * resumes the switching frequency tuning to the normal frequency * resumes channel 1 of the current regulator if it is disabled Pulling the EN pin low for a short period of approximately 200 ns achieves these same functions with little or no effect on the operation of the boost converter and the current regulator. 8.3.4 Current Limit The current limit (ICL) of the integrated MOSFET of the LM3492/-Q1 device provides a cycle-by-cycle current limit for protection. This limit can be decreased by injecting a small signal current, IILIM into the ILIM pin. The relationship between ICL and IILIM is described in Equation 2. ICL = ICL(max) - 4290 x IILIM where * ICL(max) is the maximum current limit (3.9 A typical) (2) As shown in Figure 20, create current limit functionality by connecting a resistor (RILIM) between the VCC pin and the ILIM pin. The typical voltage on the ILIM pin is 0.7 V. To obtain the maximum current limit, connect the ILIM pin to ground. VCC RILIM CVCC ILIM GND Figure 20. Programmable Current Limit 14 Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 Feature Description (continued) 8.3.5 Thermal Protection An internal thermal shutdown circuit provides thermal protection. The circuit activates at 165C (typically) to disable the LM3492/-Q1 device. In this case, the LDO regulator turns off and the CDHC pin becomes internally grounded. Thermal protection helps prevent catastrophic failures from accidental device overheating. When the junction temperature of the device drops below 145C (typical hysteresis = 20C), the device resumes normal operation. 8.3.6 Dynamic Headroom Control, Over-Ride, and Soft-Start The LM3492/-Q1 device uses dynamic headroom control (DHC) to adjust the output voltage (VOUT) of the boost converter to reduce the power loss of the current regulator and thereby maximize efficiency. To understand this control function, consider VLED,n the forward voltage of an LED string connecting to the IOUTn pin and VIOUT,n as the voltage of the IOUTn pin (where n is 1, 2 for channels 1, 2 of the current regulator). VLED,n normally and gradually decreases (in terms of minutes) as a result of the rise of the LED die temperature during operation. The DHC adjusts the output voltage (VOUT) by adjusting a threshold that is reflected in the voltage of the FB pin with reference to VIOUT,n, (the difference between VOUT and VLED,n). The capacitor CCDHC sets the sensitivity of DHC, which affects the response time on adjusting VOUT. If the capacitance value of CCDHC is small, VOUT is more sensitive to the variation of VLED,n. The CCDHC capacitor acts to control the soft-start functionality. During the start-up period, the voltage of the CDHC pin rises from 0 V to 2.25 V at a rate that depends on the value of the CCDHC capacitor. This limitation ensures that the voltage of the FB pin (as well as the output voltage) ramps up in a controlled manner, and effectively implements a soft-start function. An internal switch grounds the CDHC pin during any of the following cases: * VVCC is below the VCC UVLO threshold * a thermal shutdown occurs * the EN pin is pulled low The CDHC pin cannot be connected to the ground externally. 8.3.7 Current Regulator The LM3492/-Q1 device integrates a two-channel current regulator for controlling the current of two LED strings. The two LED strings dim individually by applying individual dimming signals to the DIM1 and DIM2 pins for LED strings 1 and 2, which are connected from the VOUT pin to the IOUT1 and IOUT2 pins. The device pulls the DIM1 and DIM2 pins low internally. The lowest contrast ratio is 1000:1. The finest pulse width of the dimming signal for the DIM1 and DIM2 pins is 300 ns. The device sets the current of an LED string (ILED) from 50 mA to 200 mA by using an external resistor RIREF connected between the IREF pin and ground. Figure 21 describes the relationship between ILED and RIREF. The two channels of the current regulator can work in parallel for only one LED string by connecting the IOUT1 and IOUT2 pins together to provide an LED current of up to 400 mA. In this case, connect the DIM1 and DIM2 pins together. Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 15 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com Feature Description (continued) Figure 21. LED Current vs Current Reference Resistance (RIREF) Figure 22. Over-Power Protection If the voltage on the IOUTn (n = 1, 2) pin is higher than 24 V when channel n is on, the regulated current of channel n reduces linearly if the voltage further increases (as shown in Figure 22). The regulated current of another channel is not affected. This over-power protection feature avoids damaging the current regulator owing to the shorting of many LEDs in one string. 8.3.8 Output Voltage Feedback The device feeds the output voltage back to the FB pin through a feedback circuit consisting of RFB1, RFB2, and CFB as shown in Figure 23. To assist the feeback functionality, maintain a value of 10 pF for CFB. The DC component of the output voltage feedback uses RFB1 and RFB2. The voltage of the FB pin VFB can be adjusted by DHC. When VFB reaches VFB-OVP, the maximum output voltage of the boost converter VOUT(max) reaches its maximum, as shown in Equation 3. VOUT(max) = 2.5 V (1 + RFB1/ RFB2) (3) During DHC operation, maintain the output voltage at a nominal voltage but not the maximum. The nominal output voltage (VOUT(nom)) is described in Equation 4. VOUT(nom) = max (VLED,n + VIOUT,n), n = 1, 2 where * * VLED,n is the forward voltage of LED string n VIOUT,n is the voltage of the IOUTn pin, where n is 1, 2 for channels 1, 2 of the current regulator) (4) The minimum value of VIOUT,n is approximately 5 x ILED. The nominal voltage of the FB pin (VFB(nom)) is recommended to be from 1.05 V to 2 V. Equation 5 describes the relation between VOUT(max), VOUT(nom), and VFB(nom): VOUT(max) = VOUT(nom) x 2.5 V / VFB(nom) (5) VOUT RFB1 CFB FB GND RFB2 Figure 23. Output Voltage Feedback Circuit 16 Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 Feature Description (continued) 8.3.9 Bidirectional Communication Pin The COMM pin of the LM3492/-Q1 device is an open-drain bidirectional I/O pin for interfacing with an external MCU for the following functions: * power-good indication * overtemperature indication * output current overvoltage and undervoltage indications * switching frequency tuning * channel 1 disabling Except for the power good indication and the overtemperature alerts, all data flow through the COMM pin is serial and is latched by the falling edge of the signal applying to the DIM1 pin, even when channel 1 of the current regulator is disabled. If the DIM1 pin remains only low or only high, either by an external circuit or by allowing it to open and pull low internally, data does not flow. Figure 24 and Figure 25 show timing diagrams of reading and writing a bit from and to the device through the COMM pin. Pull up the COMM pin by an MCU I/O pin, which has pullup capability, or an external resistor RCOMM connected to the VCC pin. Without this capability, the voltage of the COMM pin remains at zero. The rise time of the output signal of the COMM pin depends on the pullup power. If the rise time is long (RCOMM is too large or pullup power from the connecting MCU I/O pin is too weak), data may be ready after a longer duration after the falling edge. In this case, the design requires a longer delay between the falling edge latching and the (input or output) bit. Figure 24. Read from the COMM Pin Figure 25. Write to the COMM Pin 8.3.9.1 Power-Good Indication Upon start-up, the COMM pin reads low. The output voltage of the boost converter of the LM3492/-Q1 device rises until the voltage on the FB pin (VFB) reaches 2.25 V, when the COMM pin reads high to indicate powergood. The power-good indication and the signal applied on the DIM1 pin are independent. 8.3.9.2 Overtemperature Indication If the junction temperature of the LM3492/-Q1 device reaches 135C, the COMM pin reads low, showing an overtemperature indication. The external MCU considers to either turn off or reduce the brightness of the LED strings to prevent overtemperature. The overtemperature indication and the signal applied on the DIM1 pin are independent. The COMM pin reads high if the junction temperature falls below 120C. The device does not latch off and continues to operate in the presence of the overtemperature indication. Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 17 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com Feature Description (continued) 8.3.9.3 Output Current Undervoltage Indication The LM3492/-Q1 device gives an IOUTn (n = 1, 2) undervoltage indication if the voltage of the IOUTn pin when DIMn is high is lower than its minimum required voltage which can regulate ILED, and the voltage of the CDHC pin reaches its maximum. These conditions remain while the device applies 508 consecutive dimming signals on the DIMn pin. This means that the current of the LED string n does not reach the regulation value. In most cases, the IOUT undervoltage indication can be regarded as an open fault of the LED string n. A bit pattern (see Table 1) can be read from the COMM pin. The device does not latch off and continues to operate in the presence of the IOUT undervoltage indication. 8.3.9.4 Switching Frequency Tuning After power good, the switching frequency (fSW) of the LM3492/-Q1 device can be tuned down 20% or 40%, or resume normal by writing commands (refer to Table 2) to the COMM pin. This functionality helps avoid interfering some sensitive devices, for example radios, working nearby the device. Upon reset, the switching frequency (fSW) of the device resumes normal by default. In the presence of an overtemperature indication or any COMM bit pattern, no command can be written to the device. 8.4 Device Functional Modes There are no additional functional modes for this device. 8.5 Programming 8.5.1 Output Current Overvoltage Indication The LM3492/-Q1 device gives an IOUTn (n = 1, 2) overvoltage indication if the voltage of the IOUTn pin when DIMn is higher than a threshold of typically 6.5 V. These conditions remain while the device applies 508 consecutive dimming signals on the DIMn pin. The IOUT overvoltage indication can be regarded as a short fault of the LED string n except the following two cases: * powering up the device at a very low dimming ratio such that VOUT maintains at a maximum and DHC is not fast enough to reduce VOUT * during DHC override condition, a bit pattern (see Table 1) can be read from the COMM pin The device does not latch off and continues to operate in the presence of the IOUT overvoltage indication. Table 1. COMM Indication Bit Patterns CONDITION Overvoltage Undervoltage PIN BIT PATTERN IOUT1 0001 IOUT2 0011 IOUT1 0101 IOUT2 0111 8.5.2 COMM Pin Bit Pattern Table 1 summarizes all COMM bit patterns of output current overvoltage and undervoltage indications. An existing COMM bit pattern is cleared if one of the following condition occurs: * the LM3492/-Q1 device is shut down * the LM3492/-Q1 device is disabled by pulling the EN pin low * the overtemperature indication is appearing Apply the clock signal on both DIM1 and DIM2 pins when the COMM bit pattern is read by an external MCU. Before reading the COMM bit pattern, pull the EN pin low for approximately 200 ns to reset the COMM bit pattern. This situation does not affect the operation of the boost converter and the current regulator. After EN is reset, if the IOUT overvoltage or undervoltage condition lasts for 508 consecutive clock cycles, the COMM pin sends the COMM bit pattern for the MCU to read. 18 Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 In case of overtemperature, the device pulls the COMM pin low to give an overtemperature indication overriding any other pattern. After the overtemperature indication disappears, the COMM bit pattern appears before the overtemperature indication appears again. 8.5.3 Channel 1 Disable After a power good verification, channel 1 of the current regulator can be disabled by writing a command (see Table 2) to the COMM pin. If LED string 1 is malfunctioning, channel 1 can be disabled and the signal applied on the DIM1 pin can serve as only a clock signal for the data flow of the COMM pin. Channel 1 is by default enabled after reset. If the overtemperature indication or any COMM bit pattern has already presented, no command can be written to the LM3492/-Q1 device. Table 2. Channel Control Commands COMMAND BIT PATTERN fSW resume normal 1111 0111 0111 0111 fSW tune down by 20% 1111 0001 0001 0001 fSW tune down by 40% 1111 0011 0011 0011 Channel 1 disable 1111 0101 0101 0101 Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 19 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com 9 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI's customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 9.1 Application Information The LM3492/-Q1 device is ideal for automotive and marine GPS display and applications that require a high contrast ratio. 9.2 Typical Application Copyright (c) 2016, Texas Instruments Incorporated Figure 26. Typical Application Schematic 9.2.1 Design Requirements The following procedures are to design an LED driver using the LM3492/-Q1 with an input voltage ranged from 9 V to 24 V and two LED strings consists of 10 LEDs each with a forward voltage of 3.8 V for each LED when running at 200 mA. The output power is 15.2 W. The switching frequency fSW is designed to be 300 kHz. IL1(PEAK) = IL1 + ILR / 2 (6) 9.2.2 Detailed Design Procedure 9.2.2.1 RFB1, RFB2, and CFB The nominal voltage of the LED string with 10 LEDs is 38 V, and the minimum voltage of the IOUTn pin (n = 1, 2) is 1 V when ILED is 200 mA. As a result, VOUT(nom) is 39 V. Design VOUT(max) to be 65 V. From Equation 5, VFB(nom) is approximately 1.5 V, which falls in the recommended operation range from 1.05 V to 2 V. Also, design RFB2 to be 16.2 k. From Equation 3, RFB1 is calculated to be 405 k, and a standard resistor value of 402 k is selected. CFB is selected to be 10 pF as recommended. 20 Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 Typical Application (continued) 9.2.2.2 L1 The main parameter affected by the inductor is the peak to peak inductor current ripple (ILR). To maintain a continuous conduction mode (CCM) operation, ensure that the average inductor current IL1 is larger than half of ILR. For a boost converter, IL1 equals to the input current IIN. Hence, IIN = (VOUT(nom) x 2xILED ) / VIN (7) ton = (1 - VIN/VOUT) / fSW L1 = (VIN x ton) / 2IIN (8) (9) Also, If VIN is maximum, which is 24 V in this example, and only one LED string is turned on (because the two channels of the device are individually dimmable), IIN is minimum. From Equation 7 to Equation 9, it can be calculated that IIN(MIN), ton, and L1 are 0.325 A, 1.28 s, and 47 H. However, from Equation 7, IIN is maximum when VIN is minimum, which is 9 V in this example, and the two LED strings are turned on together. Hence IIN(max) is 1.73 A. Then, ILR is ILR = (VIN x ton) / L1 (10) From Equation 8, ton is 2.56 s. From (9), ILR is 0.49 A. The steady-state peak inductor current IL1(PEAK) is IL1(PEAK) = IL1 + ILR / 2 (11) As a result, IL1(PEAK) is 1.98 A. A standard value of 47 H is selected for L1, and its saturation current is larger than 1.98 A. 9.2.2.3 D1 The selection of the boost diode D1 depends on two factors. The first factor is the reverse voltage, which equals to VOUT for a boost converter. The second factor is the peak diode current at the steady state, which equals to the peak inductor current as shown in Equation 11. In this example, a 100-V, 3-A Schottky diode is selected. 9.2.2.4 CIN and COUT The function of the input capacitor CIN and the output capacitor COUT is to reduce the input and output voltage ripples. Experimentation is usually necessary to determine their value. The rated DC voltage of capacitors used should be higher than the maximum DC voltage applied. Owing to the concern of product lifetime, TI recommends ceramic capacitors. But ceramic capacitors with high rated DC voltage and high capacitance are rare in general. Multiple capacitors connecting in parallel can be used for CIN and COUT. In this example, two 10F ceramic capacitor are used for CIN, and two 2.2-F ceramic capacitor are used for COUT. 9.2.2.5 CVCC The capacitor on the VCC pin provides noise filtering and stabilizes the LDO regulator. It also prevents false triggering of the VCC UVLO. CVCC is recommended to be a 1-F, good quality and low ESR ceramic capacitor. 9.2.2.6 CCDHC The capacitor at the CDHC pin not only affects the sensitivity of the DHC but also determines the soft-start time tSS, the time for the output voltage to rise until power good. tSS is determined from the following equation: tSS = CCDHC x 2.25V 120 PA (12) In this example, CCDHC is recommended to be a 0.47-F good quality and low ESR ceramic capacitor. 9.2.2.7 RRT and RIREF The resistors RRT and RIREF set the switching frequency fSW of the boost converter and the LED current ILED respectively. From Figure 16, if fSW is 300 kHz, RRT is selected to be 442 k. From Figure 21, if ILED is 200 mA, RIREF is selected to be 6.19 k. Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 21 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com Typical Application (continued) 9.2.2.8 RCOMM Because the COMM pin is open drain, a resistor RCOMM of 52.3 k is used to connect the VCC and COMM pins to act as a pullup function. 9.2.3 Application Curve Figure 27. LED 50% Dimming, Both Channels Combined (VIN = 12 V, ILED = 150 mA, 200 Hz) 22 Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 10 Power Supply Recommendations Use a DC output power supply with a maximum output voltage capability greater than the maximum input voltage for the application. The current rating of the supply should be greater than the maximum input current required by the application. 11 Layout 11.1 Layout Guidelines The layout of the printed-circuit board is critical to optimize the performance of the LM3492/-Q1 device application circuit. In general, external components should be placed as close to the device and each other as possible to make copper traces short and direct. In particular, components of the boost converter CIN, L1, D1, COUT, and the LM3492/-Q1 device should be closed. Also, the output feedback capacitor CFB should be closed to the output capacitor COUT. The ground plane connecting the GND, PGND, and LGND pins and the exposed pad of the device and the ground connection of the CIN and COUT should be placed on the same copper layer. Good heat dissipation helps optimize the performance of the device. The ground plane should be used to connect the exposed pad of the device, which is internally connected to the device die substrate. The area of the ground plane should be extended as much as possible on the same copper layer around the device. Using numerous vias beneath the exposed pad to dissipate heat of the device to another copper layer is also a good practice. 11.2 Layout Example GND CIN EN ILIM VIN VCC SW PGND SW PGND CVCC VIN L1 D1 LED+ + VOUT RRT CFB DIM2 GND RT DIM1/CLK FB LGND RCOMM RFB1 COUT RFB2 GND COMM RIREF LED- (2) - IOUT2 IREF LED- (1) - IOUT1 CDHC CCDHC THERMAL/POWER VIA Figure 28. Layout Recommendation Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 23 LM3492, LM3492-Q1 SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 www.ti.com 12 Device and Documentation Support 12.1 Documentation Support For related documentation see the following: * AN-1656 Design Challenges of Switching LED Drivers (SNVA253) * AN-2192 LM3492 12VAC, 7W LED Driver for AR111 Application (SNOA568) * AN-2056 LM3492 Evaluation Board Reference Design (SNVA438) 12.1.1 Related Documentation 12.2 Related Links The table below lists quick access links. Categories include technical documents, support and community resources, tools and software, and quick access to sample or buy. Table 3. Related Links PARTS PRODUCT FOLDER SAMPLE & BUY TECHNICAL DOCUMENTS TOOLS & SOFTWARE SUPPORT & COMMUNITY LM3492 Click here Click here Click here Click here Click here LM3492-Q1 Click here Click here Click here Click here Click here 12.3 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document. 12.4 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TI E2ETM Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 12.5 Trademarks PowerPAD, E2E are trademarks of Texas Instruments. All other trademarks are the property of their respective owners. 12.6 Electrostatic Discharge Caution 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. 12.7 Glossary SLYZ022 -- TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 24 Submit Documentation Feedback Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 LM3492, LM3492-Q1 www.ti.com SNVS656D - SEPTEMBER 2010 - REVISED OCTOBER 2016 13 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. Copyright (c) 2010-2016, Texas Instruments Incorporated Product Folder Links: LM3492 LM3492-Q1 Submit Documentation Feedback 25 PACKAGE OPTION ADDENDUM www.ti.com 21-Nov-2015 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (C) Device Marking (4/5) LM3492MH/NOPB ACTIVE HTSSOP PWP 20 73 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LM3492 MH LM3492MHX/NOPB ACTIVE HTSSOP PWP 20 2500 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LM3492 MH LM3492QMH/NOPB ACTIVE HTSSOP PWP 20 73 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LM3492 QMH LM3492QMHX/NOPB ACTIVE HTSSOP PWP 20 2500 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LM3492 QMH (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 21-Nov-2015 Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and 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. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. OTHER QUALIFIED VERSIONS OF LM3492, LM3492-Q1 : * Catalog: LM3492 * Automotive: LM3492-Q1 NOTE: Qualified Version Definitions: * Catalog - TI's standard catalog product * Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 14-Sep-2017 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) LM3492MHX/NOPB HTSSOP PWP 20 2500 330.0 16.4 LM3492QMHX/NOPB HTSSOP PWP 20 2500 330.0 16.4 Pack Materials-Page 1 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 6.95 7.1 1.6 8.0 16.0 Q1 6.95 7.1 1.6 8.0 16.0 Q1 PACKAGE MATERIALS INFORMATION www.ti.com 14-Sep-2017 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM3492MHX/NOPB HTSSOP PWP 20 2500 367.0 367.0 35.0 LM3492QMHX/NOPB HTSSOP PWP 20 2500 367.0 367.0 35.0 Pack Materials-Page 2 MECHANICAL DATA PWP0020A MXA20A (Rev C) www.ti.com IMPORTANT NOTICE Texas Instruments Incorporated (TI) reserves the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. TI's published terms of sale for semiconductor products (http://www.ti.com/sc/docs/stdterms.htm) apply to the sale of packaged integrated circuit products that TI has qualified and released to market. Additional terms may apply to the use or sale of other types of TI products and services. Reproduction of significant portions of TI information in TI data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such reproduced documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Buyers and others who are developing systems that incorporate TI products (collectively, "Designers") understand and agree that Designers remain responsible for using their independent analysis, evaluation and judgment in designing their applications and that Designers have full and exclusive responsibility to assure the safety of Designers' applications and compliance of their applications (and of all TI products used in or for Designers' applications) with all applicable regulations, laws and other applicable requirements. Designer represents that, with respect to their applications, Designer has all the necessary expertise to create and implement safeguards that (1) anticipate dangerous consequences of failures, (2) monitor failures and their consequences, and (3) lessen the likelihood of failures that might cause harm and take appropriate actions. Designer agrees that prior to using or distributing any applications that include TI products, Designer will thoroughly test such applications and the functionality of such TI products as used in such applications. TI's provision of technical, application or other design advice, quality characterization, reliability data or other services or information, including, but not limited to, reference designs and materials relating to evaluation modules, (collectively, "TI Resources") are intended to assist designers who are developing applications that incorporate TI products; by downloading, accessing or using TI Resources in any way, Designer (individually or, if Designer is acting on behalf of a company, Designer's company) agrees to use any particular TI Resource solely for this purpose and subject to the terms of this Notice. TI's provision of TI Resources does not expand or otherwise alter TI's applicable published warranties or warranty disclaimers for TI products, and no additional obligations or liabilities arise from TI providing such TI Resources. TI reserves the right to make corrections, enhancements, improvements and other changes to its TI Resources. TI has not conducted any testing other than that specifically described in the published documentation for a particular TI Resource. Designer is authorized to use, copy and modify any individual TI Resource only in connection with the development of applications that include the TI product(s) identified in such TI Resource. NO OTHER LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE TO ANY OTHER TI INTELLECTUAL PROPERTY RIGHT, AND NO LICENSE TO ANY TECHNOLOGY OR INTELLECTUAL PROPERTY RIGHT OF TI OR ANY THIRD PARTY IS GRANTED HEREIN, including but not limited to any patent right, copyright, mask work right, or other intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information regarding or referencing third-party products or services does not constitute a license to use such products or services, or a warranty or endorsement thereof. Use of TI Resources may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. TI RESOURCES ARE PROVIDED "AS IS" AND WITH ALL FAULTS. TI DISCLAIMS ALL OTHER WARRANTIES OR REPRESENTATIONS, EXPRESS OR IMPLIED, REGARDING RESOURCES OR USE THEREOF, INCLUDING BUT NOT LIMITED TO ACCURACY OR COMPLETENESS, TITLE, ANY EPIDEMIC FAILURE WARRANTY AND ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF ANY THIRD PARTY INTELLECTUAL PROPERTY RIGHTS. TI SHALL NOT BE LIABLE FOR AND SHALL NOT DEFEND OR INDEMNIFY DESIGNER AGAINST ANY CLAIM, INCLUDING BUT NOT LIMITED TO ANY INFRINGEMENT CLAIM THAT RELATES TO OR IS BASED ON ANY COMBINATION OF PRODUCTS EVEN IF DESCRIBED IN TI RESOURCES OR OTHERWISE. IN NO EVENT SHALL TI BE LIABLE FOR ANY ACTUAL, DIRECT, SPECIAL, COLLATERAL, INDIRECT, PUNITIVE, INCIDENTAL, CONSEQUENTIAL OR EXEMPLARY DAMAGES IN CONNECTION WITH OR ARISING OUT OF TI RESOURCES OR USE THEREOF, AND REGARDLESS OF WHETHER TI HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Unless TI has explicitly designated an individual product as meeting the requirements of a particular industry standard (e.g., ISO/TS 16949 and ISO 26262), TI is not responsible for any failure to meet such industry standard requirements. Where TI specifically promotes products as facilitating functional safety or as compliant with industry functional safety standards, such products are intended to help enable customers to design and create their own applications that meet applicable functional safety standards and requirements. Using products in an application does not by itself establish any safety features in the application. Designers must ensure compliance with safety-related requirements and standards applicable to their applications. Designer may not use any TI products in life-critical medical equipment unless authorized officers of the parties have executed a special contract specifically governing such use. Life-critical medical equipment is medical equipment where failure of such equipment would cause serious bodily injury or death (e.g., life support, pacemakers, defibrillators, heart pumps, neurostimulators, and implantables). Such equipment includes, without limitation, all medical devices identified by the U.S. Food and Drug Administration as Class III devices and equivalent classifications outside the U.S. TI may expressly designate certain products as completing a particular qualification (e.g., Q100, Military Grade, or Enhanced Product). Designers agree that it has the necessary expertise to select the product with the appropriate qualification designation for their applications and that proper product selection is at Designers' own risk. Designers are solely responsible for compliance with all legal and regulatory requirements in connection with such selection. Designer will fully indemnify TI and its representatives against any damages, costs, losses, and/or liabilities arising out of Designer's noncompliance with the terms and provisions of this Notice. Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright (c) 2017, Texas Instruments Incorporated Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Texas Instruments: LM3492MH/NOPB LM3492MHX/NOPB