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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

LM3492/-Q1 Two-Channel Individual Dimmable LED Driver With Boost Converter and Fast

Current Regulator

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 Projected-

On-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 mΩ, 3.9-A

N-Channel MOSFET switch minimizes the solution

size.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)

LM3492 HTSSOP (20) 7.80 mm × 4.40 mm

LM3492-Q1

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Typical Application

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Table of Contents

1 Features.................................................................. 1

2 Applications ........................................................... 1

3 Description............................................................. 1

4 Revision History..................................................... 2

5 Description (continued)......................................... 3

6 Pin Configuration and Functions......................... 4

7 Specifications......................................................... 5

7.1 Absolute Maximum Ratings ...................................... 5

7.2 ESD Ratings.............................................................. 5

7.3 Recommended Operating Conditions....................... 5

7.4 Thermal Information.................................................. 5

7.5 Electrical Characteristics........................................... 6

7.6 Typical Characteristics.............................................. 8

8 Detailed Description............................................ 11

8.1 Overview................................................................. 11

8.2 Functional Block Diagram....................................... 12

8.3 Feature Description................................................. 12

8.4 Device Functional Modes........................................ 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 Documentation Support ........................................ 24

12.2 Related Links ........................................................ 24

12.3 Receiving Notification of Documentation Updates 24

12.4 Community Resources.......................................... 24

12.5 Trademarks........................................................... 24

12.6 Electrostatic Discharge Caution............................ 24

12.7 Glossary................................................................ 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 RθJA value from 32.7 to 36.5 in the Thermal Information table............................................................................... 5

Changes from Revision B (May 2013) to Revision C Page

• Changed layout of National Data Sheet to TI format ........................................................................................................... 20

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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.

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LM3492-Q1

SNVS656D –SEPTEMBER 2010–REVISED OCTOBER 2016

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6 Pin Configuration and Functions

PWP PowerPAD™ Package

20-Pin HTSSOP

Top View

Pin Functions

PIN I/O DESCRIPTION APPLICATION INFORMATION

NO. NAME

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.

3SW 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

9 IOUT2 I Current Regulator Input

of Channel 2 Input of the current regulator of channel 2. The regulated current is programmable

(refer to the IREF pin).

10 IOUT1 I Current Regulator Input

of Channel 1 Input of the current regulator of channel 1. The regulated current is programmable

(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-µA 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-µA 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-µA current.

17 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 µF 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.

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(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.

7 Specifications

7.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)

MIN MAX UNIT

Input voltage VIN, RT, VOUT to GND −0.3 67 VSW to GND −0.3 67

SW to GND (Transient) −2 (<100 ns)

Output voltage ILIM to GND −0.3 0.3 VFB to GND −0.3 5

COMM, DIM1, DIM2, to GND –0.3 6

Junction temperature, TJ150 150 °C

Storage temperature, Tstg −65 150 °C

(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

7.2 ESD Ratings VALUE UNIT

V(ESD) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V

Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±750

7.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted) MIN MAX UNIT

Supply voltage, VIN 4.5 65 V

Operation temperature, TA–40 125 °C

(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application

report.

7.4 Thermal Information

THERMAL METRIC(1) LM3492, LM3492-Q1

UNITPWP (HTSSOP)

20 PINS

RθJA Junction-to-ambient thermal resistance 36.5 °C/W

RθJC(top) Junction-to-case (top) thermal resistance 20.8 °C/W

RθJB Junction-to-board thermal resistance 17.5 °C/W

ψJT Junction-to-top characterization parameter 0.5 °C/W

ψJB Junction-to-board characterization parameter 17.4 °C/W

RθJC(bot) Junction-to-case (bottom) thermal resistance 2 °C/W

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(1) The VCC pin provides self bias for the internal gate drive and control circuits. Device thermal limitations limit external loading.

7.5 Electrical Characteristics

over operating free-air temperature range, VIN = 12 V (unless otherwise noted)

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

START-UP REGULATOR (VCC PIN)

VVCC Output voltage CVCC = 0.47 µF, no load 4.7 5.5 6.3 V

IVCC = 2 mA 4.7 5.5 6.3 V

VCC_UVLO VCC pin undervoltage lockout

threshold (UVLO) VVCC increasing, TA= TJ= 25°C 3.56 3.78 4 V

VCC_UVLO-HYS VCC pin UVLO hysteresis VVCC decreasing 310 mV

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 µA

IVCC VCC pin current limit (1) VVCC = 0 V 18 30 mA

VCC-VOUT VCC pin output voltage when

supplied by VOUT VIN = Open, IVCC = 1 mA,

VOUT = 18 V, TA= TJ= 25°C 3.5 4.1 4.7 V

ENABLE INPUT

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 µA

IEN-OPER Enable pullup current during

operation VEN = 2 V 40 µA

CURRENT REGULATOR

VIREF IREF pin voltage 4.5 V ≤VIN ≤65 V 1.231 1.256 1.281 V

VDHC50 VIOUT under DHC IOUT = 50 mA, RIREF = 25 kΩ0.16 0.225 0.29 VVDHC100 IOUT = 100 mA, RIREF = 12.5 kΩ0.38 0.48 0.58

VDHC200 IOUT = 200 mA, RIREF = 6.25 kΩ0.81 0.99 1.17

IOUT50

Current output under DHC

VIOUT = VDHC50, RIREF = 25 kΩ,

TA= TJ= 25°C 47.5 50 52.5

VIOUT = VDHC50, RIREF = 25 kΩ46.5 50 53.5

IOUT100

VIOUT = VDHC100, RIREF = 12.5 kΩ,

TA= TJ= 25°C 97 100 103

VIOUT = VDHC100, RIREF = 12.5 kΩ96 100 104

IOUT200

VIOUT = VDHC200, RIREF = 6.25 kΩ,

TA= TJ= 25°C 194 200 206

VIOUT = VDHC200, RIREF = 6.25 kΩ192 200 208

IOUTOFF Leakage at maximum work voltage VDIM = 0, VIOUT = 65 V, TA= TJ=

25°C 5 µA

VIOUT50-MIN

Minimum work voltage

IOUT = 50 mA, RIREF = 25 kΩ,

IOUT = 0.98 × IOUT50, TA= TJ= 25°C 0.1 0.15

VIOUT100-MIN IOUT = 100 mA, RIREF = 12.5 kΩ,

IOUT = 0.98 × IOUT100,

TA= TJ= 25°C 0.2 0.35

VIOUT200-MIN IOUT = 200 mA, RIREF = 6.25 kΩ,

IOUT = 0.98 × IOUT200,

TA= TJ= 25°C 0.4 0.65

VDIM-HIGH DIM voltage HIGH 1.17 V

VDIM-LOW DIM voltage LOW 0.7 V

BOOST CONVERTER

ICDHC-SRC CDHC pin source current VCDHC = 1.6 V, VFB = 3 V,

VIOUT = 0 V, DIM = High 60 µA

ICDHC-SINK CDHC pin sink current VCDHC = 1.6 V, VFB = 3 V,

VIOUT = 3 V, DIM = High 56 µA

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Electrical Characteristics (continued)

over operating free-air temperature range, VIN = 12 V (unless otherwise noted)

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

ICDHC-LEAKAGE CDHC pin leakage current DIM = Low, VCDHC = 2.6 V, TA= TJ

= 25°C 5 46 nA

ICL-MAX Integrated MOSFET peak current

limit threshold 3.3 3.9 4.5 A

ICL-HALF Half integrated MOSFET peak

current limit threshold RILIM = 11 kΩ2 A

RDS(on) Integrated MOSFET On-resistance ISW = 500 mA 0.19 0.43 Ω

VFBTH-PWRGD Power-Good FB pin threshold 2.25 V

IFB Feedback pin input current VFB = 3 V, TA= TJ= 25°C 1 µA

tON ON timer pulse width

VIN = 12 V, VOUT = 65 V,

RRT = 300 kΩ1460

VIN = 24 V, VOUT = 32.5 V,

RRT = 300 kΩ800

VIN = 12 V, VOUT = 65 V,

RRT = 100 kΩ550

VIN = 24 V, VOUT = 32.5 V,

RRT = 100 kΩ350

tON(min)ILIM ON timer minimum pulse width at

current limit 145 ns

tOFF OFF timer pulse width 145 350 ns

COMM PIN

VIOUT-OV IOUT pin overvoltage threshold COMM goes LOW during VIOUT

rising, other VIOUT = 1.2 V 5.6 6.7 7.8 V

VCOMM-LOW COMM pin at LOW 5 mA into COMM 0.7 V

ILEAK-FAULT COMM pin open leakage VCOMM = 5 V 5 µA

THERMAL PROTECTION

TOTM Overtemperature indication TJrising 135 °C

TOTM-HYS Overtemperature indication

hysteresis TJfalling 15 °C

TSD Thermal shutdown temperature TJrising 165 °C

TSD-HYS Thermal shutdown temperature

hysteresis TJfalling 20 °C

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7.6 Typical Characteristics

Unless otherwise specified the following conditions apply: TJ= 25°C, VIN = 12 V with configuration in typical application circuit

for ILED = 200 mA shown in this data sheet.

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

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Typical Characteristics (continued)

Unless otherwise specified the following conditions apply: TJ= 25°C, 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)

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Typical Characteristics (continued)

Unless otherwise specified the following conditions apply: TJ= 25°C, 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) Figure 14. 300-ns LED Dimming Pulse Width (ILED = 0.2 A,

Dimming frequency = 3.33 kHz)

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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 on-

period, 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.

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8.2 Functional Block Diagram

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.

Output Voltage (V)

Switching Frequency (kHz)

24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

300

330

360

390

420

450

480

510

540

570

600

D001

Input Voltage (V)

Switching Frequency (kHz)

6 8 10 12 14 16 18 20 22 24 26

200

240

280

320

360

400

440

480

520

560

600

D001

RRT (k:)

Switching Frequency (kHz)

100 200 300 400 500 600 700 800

150

250

350

450

550

650

750

850

950

D001

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Feature Description (continued)

ILED = 150 mA VOUT = 30 V VVIN = 12 V

Figure 16. Switching Frequency vs RT Resistance

ILED = 150 mA VOUT = 30 V RRT = 274 kΩ

Figure 17. Switching Frequency vs Input Voltage

ILED = 150 mA RRT = 274 kΩVVIN = 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-µF 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-µA 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 µA. 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.

VCC

ILIM GND

RILIM

CVCC

VIN

EN GND

REN1

REN2

VVIN

DEN

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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.

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 × 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.

Figure 20. Programmable Current Limit

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Feature Description (continued)

8.3.5 Thermal Protection

An internal thermal shutdown circuit provides thermal protection. The circuit activates at 165°C (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 145°C (typical hysteresis = 20°C), 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 IOUTnpin 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.

VOUT

FB GND

RFB1 CFB

RFB2

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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 Ω× 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) × 2.5 V / VFB(nom) (5)

Figure 23. Output Voltage Feedback Circuit

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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 power-

good. 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 135°C, 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 120°C. The device does not latch

off and continues to operate in the presence of the overtemperature indication.

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Product Folder Links: LM3492 LM3492-Q1

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 PIN BIT PATTERN

Overvoltage IOUT1 0001

IOUT2 0011

Undervoltage 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.

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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

LM3492

LM3492-Q1

SNVS656D –SEPTEMBER 2010–REVISED OCTOBER 2016

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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

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 kΩ. From Equation 3, RFB1 is calculated to be 405 kΩ, and a standard resistor value of 402 kΩis

selected. CFB is selected to be 10 pF as recommended.

tSS = CCDHC x 2.25V

120 PA

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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) × 2×ILED ) / VIN (7)

Also,ton = (1 – VIN/VOUT) / fSW (8)

L1= (VIN × ton) / 2IIN (9)

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 L1are 0.325 A, 1.28 µs, and 47 µH. 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 µs. 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 µH 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 D1depends 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 10-

µF ceramic capacitor are used for CIN, and two 2.2-µF 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-µF, 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:

(12)

In this example, CCDHC is recommended to be a 0.47-µF 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 kΩ. From Figure 21, if ILED is 200 mA,

RIREF is selected to be 6.19 kΩ.

LM3492

LM3492-Q1

SNVS656D –SEPTEMBER 2010–REVISED OCTOBER 2016

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Typical Application (continued)

9.2.2.8 RCOMM

Because the COMM pin is open drain, a resistor RCOMM of 52.3 kΩis 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)

VIN

VOUT

ILIM

VCC

PGND

DIM2

THERMAL/POWER VIA

GND

VIN CVCC

CCDHC

RCOMM

RIREF

RRT

CIN

COUT

LED+

LED- (2)

GND

IOUT2

IOUT1

DIM1/CLK

LGND

COMM

IREF

CDHC

RFB1

RFB2

CFB

LED- (1)

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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

Figure 28. Layout Recommendation

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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 E2E™ 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.

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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.

PACKAGE OPTION ADDENDUM

www.ti.com 21-Nov-2015

Addendum-Page 1

PACKAGING INFORMATION

Orderable Device Status

(1)

Package Type Package

Drawing Pins Package

Qty Eco Plan

(2)

Lead/Ball Finish

(6)

MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

LM3492MH/NOPB ACTIVE HTSSOP PWP 20 73 Green (RoHS

& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LM3492

LM3492MHX/NOPB ACTIVE HTSSOP PWP 20 2500 Green (RoHS

& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LM3492

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.

PACKAGE OPTION ADDENDUM

www.ti.com 21-Nov-2015

Addendum-Page 2

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

TAPE AND REEL INFORMATION

*All dimensions are nominal

Device Package

Type Package

Drawing Pins SPQ Reel

Diameter

(mm)

Reel

Width

W1 (mm)

(mm) B0

(mm) K0

(mm) P1

(mm) W

(mm) Pin1

Quadrant

LM3492MHX/NOPB HTSSOP PWP 20 2500 330.0 16.4 6.95 7.1 1.6 8.0 16.0 Q1

LM3492QMHX/NOPB HTSSOP PWP 20 2500 330.0 16.4 6.95 7.1 1.6 8.0 16.0 Q1

PACKAGE MATERIALS INFORMATION

www.ti.com 14-Sep-2017

Pack Materials-Page 1

*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

PACKAGE MATERIALS INFORMATION

www.ti.com 14-Sep-2017

Pack Materials-Page 2

MECHANICAL DATA

PWP0020A

www.ti.com

MXA20A (Rev C)

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