LM3492HCQMH/NOPB [TI]
具有升压转换器和电流调节器的汽车类高对比度 2 通道可调光 LED 驱动器 | PWP | 20 | -40 to 125;
| 型号： | LM3492HCQMH/NOPB |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | 具有升压转换器和电流调节器的汽车类高对比度 2 通道可调光 LED 驱动器 | PWP | 20 | -40 to 125 升压转换器 驱动 光电二极管 接口集成电路 驱动器 调节器 |
| 文件： | 总30页 (文件大小：1459K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
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LM3492HC-Q1, LM3492HC
ZHCSEC6B –MARCH 2012–REVISED OCTOBER 2015
LM3492HC/-Q1 具有升压转换器和快速电流调节器的
双通道、独立可调光 LED 驱动器
1 特性
2 应用
1
•
升压转换器
•
使用多达 28 个 LED 提供背光照明的 6.5” 至 10”
超高对比度液晶显示屏 (LCD)
–
–
–
–
–
汽车级产品，符合 Q100 1 级要求
极宽输入电压范围：4.5V 至 65V
可编程软启动周期
•
汽车或航海全球定位系统 (GPS) 显示屏
3 说明
无需环路补偿
LM3492HC/-Q1 器件集成了一个升压转换器和一个双
通道电流调节器，以实现一款高效且经济实用的 LED
驱动器。 该器件能够以 15W 最大功耗以及最高可达
65V 的输出电压驱动两个独立可调光 LED 灯串。升压
转换器采用一种专有的预计导通时间控制方法提供快速
瞬态响应，无需进行补偿。 近似恒定的开关频率可在
200kHz 至 1MHz 范围内进行设定。 陶瓷电容可使应
用电路保持稳定状态，并且在调光过程中不会产生可闻
性噪声。 可编程峰值电流限值和软启动功能降低了启
动时的浪涌电流。 集成的 190mΩ、3.9A、N 沟道金属
氧化物半导体场效应晶体管 (MOSFET) 开关最大限度
地缩减了解决方案的尺寸。 快速转换的电流调节器支
持应用高频和窄脉宽调光信号，可实现 10000:1 的超
高对比度。LED 电流可通过单个电阻在 50mA 至 250
mA 的范围内进行设置。
与陶瓷电容及其他低等效串联电阻 (ESR) 电容
配合使用时可保持稳定，无可闻性噪声产生
–
近似恒定的开关频率可在 200kHz 至 1MHz 范
围内进行编程
•
电流调节器
–
可编程发光二极管 (LED) 电流：50mA 至
250mA
–
–
10000：1 对比度，300ns 最小脉宽
两个独立可调光 LED 灯串的电压高达 65V，总
功耗为 15W（电流为 150mA 时通常为 28 个
LED）
–
–
–
动态余量控制可实现效率最大化
过载保护
±3% 电流精度
•
监控功能
–
–
–
–
精密使能
器件信息(1)
用于诊断和命令的 COMM I/O 引脚
热关断保护
器件型号
LM3492HC
LM3492HC-Q1
封装
封装尺寸（标称值）
PWP (20)
6.50mm x 4.40mm
20 引脚耐热增强型 PWP 封装
(1) 要了解所有可用封装，请见数据表末尾的可订购产品附录。
简化应用
L1
LM3492HC
LM3492HC-Q1
VIN
SW
CIN
RRT
CFB
RFB1
CDHC
VCC
EN
RT
VOUT
FB
CCDHC
COUT
CVCC
RIREF
RCOMM
PGND
GND
IREF
ILIM
RFB2
COMM
LGND
DIM1/CLK IOUT1
DIM2 IOUT2
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.
English Data Sheet: SNVS797
LM3492HC-Q1, LM3492HC
ZHCSEC6B –MARCH 2012–REVISED OCTOBER 2015
www.ti.com.cn
目录
8.4 Device Functional Modes........................................ 17
8.5 Programming .......................................................... 18
Application and Implementation ........................ 19
9.1 Application Information............................................ 19
9.2 Typical Application ................................................. 19
1
2
3
4
5
6
7
特性.......................................................................... 1
应用.......................................................................... 1
说明.......................................................................... 1
修订历史记录 ........................................................... 2
说明（继续） ........................................................... 3
Pin Configuration and Functions......................... 3
Specifications......................................................... 4
7.1 Absolute Maximum Ratings ...................................... 4
7.2 ESD Ratings.............................................................. 4
7.3 Recommended Operating Conditions....................... 4
7.4 Thermal Information.................................................. 5
7.5 Electrical Characteristics........................................... 5
7.6 Typical Characteristics.............................................. 7
Detailed Description ............................................ 11
8.1 Overview ................................................................. 11
8.2 Functional Block Diagram ....................................... 11
8.3 Feature Description................................................. 12
9
10 Power Supply Recommendations ..................... 22
11 Layout................................................................... 22
11.1 Layout Guidelines ................................................. 22
11.2 Layout Example .................................................... 22
12 器件和文档支持 ..................................................... 23
12.1 相关链接................................................................ 23
12.2 社区资源................................................................ 23
12.3 商标....................................................................... 23
12.4 静电放电警告......................................................... 23
12.5 Glossary................................................................ 23
13 机械、封装和可订购信息....................................... 23
8
4 修订历史记录
注：之前版本的页码可能与当前版本有所不同。
Changes from Revision A (May 2013) to Revision B
Page
•
已添加 引脚配置和功能部分，ESD 额定值表，特性描述部分，器件功能模式，应用和实施部分，电源相关建议部分，
布局部分，器件和文档支持部分以及机械、封装和可订购信息部分........................................................................................ 1
2
版权 © 2012–2015, Texas Instruments Incorporated
LM3492HC-Q1, LM3492HC
www.ti.com.cn
ZHCSEC6B –MARCH 2012–REVISED OCTOBER 2015
5 说明（继续）
为了实现效率最大化，动态余量控制 (DHC) 将输出电压自动调节为最小值。 不同尺寸的背光面板对于灯串中 LED
数量的要求各异，DHC 为此提供单一物料清单 (BOM)，从而缩短总体开发时间并削减总成本。 LM3492HC 器件的
COMM 引脚用作双向 I/O 引脚。 通用的 COMM 引脚与外部微控制器 (MCU) 相连，能够提供以下功能：电源正
常、过热、IOUT 过压和欠压指示、开关频率调整以及通道 1 禁用。 该器件的其他监视功能包括：精密使能、VCC
欠压锁定、电流调节器过载保护以及热关断保护。 该器件采用 20 引脚耐热增强型 PWP 封装。
6 Pin Configuration and Functions
PWP Package
20 Pin HTSSOP
Top View
1
EN
VIN
20
19
18
17
16
15
14
13
12
11
ILIM
2
VCC
3
SW
PGND
PGND
DIM2
4
SW
VOUT
RT
5
DIM1/CLK
6
Exposed
Thermal
Pad
7
FB
LGND
COMM
IREF
GND
IOUT2
IOUT1
8
9
10
CDHC
NC – No internal connection
Pin Functions
PIN
TYPE(1)
DESCRIPTION
NAME
NO.
Dynamic headroom control. An external capacitor connected to this pin sets the DHC sensitivity. At
start-up, a 12- µA internal current source charges an external capacitor to provide a soft-start
function.
CDHC
11
I
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).
COMM
13
15
I/O
I/O
Dimming control of channel 1. Control the on and 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 and
output data of the COMM pin.
DIM1/CLK
Dimming control of channel 2. Control the on and off of the current regulator of channel 2. This pin is
internally pulled low by a 5-µA current.
DIM2
EN
16
1
I
I
Enable input. Contains an internal pullup. Connect to a voltage higher than 1.63 V to provide
precision enable for the device.
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.
FB
7
8
I
G
I
GND
ILIM
Analog signal ground. Connect to the exposed pad directly beneath the device.
Peak current limit adjust. Connecting an external resistor from the ILIM pin to the VCC pin reduces
peak current limit. Connect the ILIM pin to ground to obtain the maximum current limit.
20
Current regulator input for channel 1. Input of the current regulator of channel 1. The regulated
current is programmable (see the IREF pin).
IOUT1
IOUT2
IREF
10
9
I
I
Current regulator input for channel 2. Input of the current regulator of channel 2. The regulated
current is programmable (see the IREF pin).
Current setting pin for the current regulators. An external resistor connected from this pin to ground
programs the regulated current of the current regulator of channels 1 and 2.
12
14
I
Current regulator ground. Must be connected to the GND pin and exposed pad for normal operation.
The LGND and GND pins are not internally connected.
LGND
G
(1) I = Input, O = Output, G = Ground
Copyright © 2012–2015, Texas Instruments Incorporated
3
LM3492HC-Q1, LM3492HC
ZHCSEC6B –MARCH 2012–REVISED OCTOBER 2015
www.ti.com.cn
Pin Functions (continued)
PIN
TYPE(1)
DESCRIPTION
NAME
NO.
17
Integrated MOSFET ground. Must be connected to the GND pin and exposed pad for normal
operation. The PGND and GND pins are not internally connected.
PGND
G
I
18
Frequency control pin. An external resistor from the VOUT pin to this pin sets the switching
frequency.
RT
6
3
4
SW
VCC
I
Switch node. Internally connected to the drain of the integrated MOSFET.
Internal LED regulator output. Nominally regulated to 5.5 V. Connect a capacitor of 0.47-μF or larger
between the VCC and GND pins.
19
O
VIN
2
5
I
I
Input supply voltage pin. Input voltage range is from 4.5 V to 65 V.
VOUT
Output voltage sense pin. Senses the output voltage for nearly constant switching frequency control.
Thermal connection pad. Connect to a ground plane.
Exposed Pad
G
7 Specifications
7.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)
(1)
MIN
MAX
67
−2
1
UNIT
VIN, RT, VOUT to GND, SW to GND
Input voltage
−0.3
V
SW to GND (transient <100 ns)
ILIM to GND
−0.3
−0.3
−0.3
Output voltage
FB to GND
5
V
COMM, DIM1, DIM2, to GND
6
Junction temperature, TJ
Storage temperature, Tstg
150
150
°C
–65
(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.
7.2 ESD Ratings
VALUE
±2000
±750
UNIT
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1)
Charged-device model (CDM), per JEDEC specification JESD22-C101(2)
V(ESD)
Electrostatic discharge
V
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. Pins listed as ±2000
V may actually have higher performance.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. Pins listed as ±750 V
may actually have higher performance.
7.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
4.5
NOM
MAX
65
UNIT
V
Supply input voltage, VIN
Junction temperature, TJ
−40
125
°C
4
Copyright © 2012–2015, Texas Instruments Incorporated
LM3492HC-Q1, LM3492HC
www.ti.com.cn
ZHCSEC6B –MARCH 2012–REVISED OCTOBER 2015
7.4 Thermal Information
LM3492HC
PWP
UNIT
THERMAL METRIC(1)
(HTSSOP)
20 PINS
RθJA
Junction-to-ambient thermal resistance
Junction-to-case (top) thermal resistance
Junction-to-board thermal resistance
36.8
21.8
18.3
0.6
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
RθJC(top)
RθJB
ψJT
Junction-to-top characterization parameter
Junction-to-board characterization parameter
Junction-to-case (bottom) thermal resistance
ψJB
18.1
2
RθJC(bot)
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
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)
CVCC = 0.47 µF, no load
IVCC = 2 mA
4.7
4.7
5.5
5.5
6.3
6.3
V
V
VVCC
Output voltage
VCC pin undervoltage lockout
threshold (UVLO)
VCC_UVLO
VVCC increasing, TA = TJ = 25°C
3.56
3.78
4
V
VCC_UVLO-HYS
IIN
VCC pin UVLO hysteresis
IIN operating current
VVCC decreasing, TA = TJ = 25°C
No switching, VFB = 0 V
310
3.6
mV
mA
5.2
95
IIN operating current, device
shutdown
IIN-SD
VEN = 0 V
30
30
µA
mA
V
(1)
IVCC
VCC pin current limit
VVCC = 0 V
18
VCC pin output voltage when
supplied by VOUT
VIN = Open, IVCC = 1 mA,
VOUT = 18 V
VCC-VOUT
3.5
4.1
4.7
ENABLE INPUT
VEN
EN pin input threshold
VEN rising
VEN falling
VEN = 0 V
1.55
1.63
194
2
1.71
V
VEN-HYS
EN pin threshold hysteresis
Enable pullup current at shutdown
mV
µA
IEN-SHUT
Enable pullup current during
operation
IEN-OPER
VEN = 2 V
40
µA
CURRENT REGULATOR
VIREF
IREF pin voltage
4.5 V ≤ VIN ≤ 65 V
1.231
0.160
0.38
1.256
0.225
0.48
1.281
0.290
0.58
V
VDHC50
VDHC100
VDHC200
VDHC250
IOUT = 50 mA, RIREF = 25 kΩ
IOUT = 100 mA, RIREF = 12.5 kΩ
IOUT = 200 mA, RIREF = 6.25 kΩ
IOUT = 250 mA, RIREF = 5 kΩ
VIOUT under DHC
V
0.81
0.99
1.17
0.81
1.21
1.44
(1) The VCC pin provides self bias for the internal gate drive and control circuits. Device thermal limitations limit external loading.
Copyright © 2012–2015, Texas Instruments Incorporated
5
LM3492HC-Q1, LM3492HC
ZHCSEC6B –MARCH 2012–REVISED OCTOBER 2015
www.ti.com.cn
Electrical Characteristics (continued)
over operating free-air temperature range, VIN = 12 V (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
47.5
46.5
97
TYP
50
MAX
UNIT
VIOUT = VDHC50, RIREF = 25 kΩ,
TA = TJ = 25°C
52.5
53.5
103
IOUT50
VIOUT = VDHC50, RIREF = 25 kΩ
50
VIOUT = VDHC100, RIREF = 12.5 kΩ,
TA = TJ = 25°C
100
100
200
200
250
250
IOUT100
IOUT200
IOUT250
VIOUT = VDHC100, RIREF = 12.5 kΩ
96
104
Current output under DHC
mA
VIOUT = VDHC200, RIREF = 6.25 kΩ,
TA = TJ = 25°C
194
192
241.3
238
206
VIOUT = VDHC200, RIREF = 6.25 kΩ
208
VIOUT = VDHC250, RIREF = 5 kΩ,
TA = TJ = 25°C
258.8
VIOUT = VDHC250, RIREF = 5 kΩ
262
5
IOUTOFF
Leakage at maximum work voltage
VDIM = 0, VIOUT = 65 V
µA
IOUT = 50 mA, RIREF = 25 kΩ,
IOUT = 0.98 × IOUT50, TA = TJ = 25°C
VIOUT50-MIN
0.1
0.2
0.15
IOUT = 100 mA, RIREF = 12.5 kΩ,
VIOUT100-MIN
VIOUT200-MIN
VIOUT250-MIN
IOUT = 0.98 × IOUT100
,
0.35
TA = TJ = 25°C
Minimum work voltage
V
IOUT = 200 mA, RIREF = 6.25 kΩ,
IOUT = 0.98 × IOUT200
,
0.4
0.5
0.65
0.82
TA = TJ = 25°C
IOUT = 250 mA, RIREF = 5 kΩ,
IOUT = 0.98 × IOUT250, TA = TJ =
25°C
VDIM-HIGH
VDIM-LOW
DIM voltage HIGH
DIM voltage LOW
1.17
V
V
0.7
BOOST CONVERTER
VCDHC = 1.6 V, VFB = 3 V,
VIOUT = 0 V, DIM = High
ICDHC-SRC
ICDHC-SINK
ICDHC-PULLUP
ICL-MAX
CDHC pin source current
60
56
µA
µA
nA
A
VCDHC = 1.6 V, VFB = 3 V,
VIOUT = 3 V, DIM = High
CDHC pin sink current
CDHC pin pullup current
DIM = Low, VCDHC = 2.3 V,
VFB = 3 V
10
200
3.9
2
500
4.5
Integrated MOSFET peak current
limit threshold
3.3
Half integrated MOSFET peak
current limit threshold
ICL-HALF
RILIM = 11 kΩ
A
RDS(on)
Integrated MOSFET On-resistance
Power-Good FB pin threshold
ISW = 500 mA
0.19
2.25
0.43
Ω
VFBTH-PWRGD
V
VFB rising, VCDHC = 4 V
VFB falling
2.64
0.1
2.76
2.88
0.323
1
FB pin overvoltage protection
threshold FB pin OVP hysteresis
VFB-OVP
IFB
V
0.215
Feedback pin input current
VFB = 3 V
µA
VIN = 12 V, VOUT = 65V,
RRT = 300 kΩ
1460
800
550
350
VIN = 24 V, VOUT = 32.5V,
RRT = 300 kΩ
tON
ON timer pulse width
ns
VIN = 12 V, VOUT = 65V,
RRT = 100 kΩ
VIN = 24 V, VOUT = 32.5V,
RRT = 100 kΩ
ON timer minimum pulse width at
current limit
tON(min)ILIM
tOFF
145
145
ns
ns
OFF timer pulse width
350
6
Copyright © 2012–2015, Texas Instruments Incorporated
LM3492HC-Q1, LM3492HC
www.ti.com.cn
ZHCSEC6B –MARCH 2012–REVISED OCTOBER 2015
Electrical Characteristics (continued)
over operating free-air temperature range, VIN = 12 V (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
COMM PIN
COMM goes LOW during VIOUT
rising, other VIOUT = 1.2 V
VIOUT-OV
IOUT pin overvoltage threshold
5.6
6.7
7.8
V
VCOMM-LOW
ILEAK-FAULT
COMM pin at LOW
5 mA into COMM
VCOMM = 5 V
0.7
5
V
COMM pin open leakage
µA
THERMAL PROTECTION
TOTM
Overtemperature indication
TJ rising
TJ falling
TJ rising
TJ falling
135
15
°C
°C
°C
°C
Over-temperature indication
hysteresis
TOTM-HYS
TSD
Thermal shutdown temperature
165
20
Thermal shutdown temperature
hysteresis
TSD-HYS
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 = 250 mA shown in this data sheet.
Figure 1. Quiescent Current vs Input Voltage
Figure 2. VCC Voltage vs VCC Ouput Current
Figure 3. VCC Voltage vs Input Voltage
Figure 4. Switching Frequency vs Input Voltage
Copyright © 2012–2015, Texas Instruments Incorporated
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LM3492HC-Q1, LM3492HC
ZHCSEC6B –MARCH 2012–REVISED OCTOBER 2015
www.ti.com.cn
Typical Characteristics (continued)
Unless otherwise specified the following conditions apply: TJ = 25°C, VIN = 12 V with configuration in typical application circuit
for ILED = 250 mA shown in this data sheet.
Figure 5. LED Current Regulation vs Temperature
Figure 6. MOSFET On-Resistance vs Temperature
100
1.00
0.75
95
-40°C
0.50
0.25
25°C
90
85
0.00
25°C
-40°C
-0.25
-0.50
-0.75
-1.00
80
75
70
125°C
125°C
20
10
15
20
25
10
15
25
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
ILED = 0.25 A
Figure 7. Efficiency vs Input Voltage
ILED = 0.25 A
Figure 8. LED Current Regulation vs Input Voltage
ILED = 0.25 A
Figure 9. Power-Up Waveform
ILED = 0.25 A
Figure 10. Enable Transient Waveform
8
Copyright © 2012–2015, Texas Instruments Incorporated
LM3492HC-Q1, LM3492HC
www.ti.com.cn
ZHCSEC6B –MARCH 2012–REVISED OCTOBER 2015
Typical Characteristics (continued)
Unless otherwise specified the following conditions apply: TJ = 25°C, VIN = 12 V with configuration in typical application circuit
for ILED = 250 mA shown in this data sheet.
ILED = 0.25 A
Dimming frequency = 200 Hz
Figure 12. LED 50% Dimming Waveforms
Figure 11. Steady-State Operation
ILED = 0.25 A
Dimming frequency = 200 Hz
ILED = 0.25 A
Dimming frequency = 200 Hz
Figure 14. 10000:1 LED Dimming Waveforms
Figure 13. 1000:1 LED Dimming Waveforms
800
750
700
650
600
550
500
450
400
350
300
250
200
320
300
280
260
240
220
200
180
160
VOUT = 27V
VOUT = 30V
VOUT = 33V
VOUT = 36V
VOUT = 27V
VOUT = 30V
VOUT = 33V
VOUT = 36V
6
8
10
12
14
16
18
20
22
24
26
6
8
10
12
14
16
18
20
22
24
Input Voltage (V)
Input Voltage (V)
D001
D001
ILED = 0.15 A
RRT = 178 kΩ
ILED = 0.15 A
RRT = 499 kΩ
Figure 15. Switching Frequency vs Input Voltage
Figure 16. Switching Frequency vs Input Voltage
Copyright © 2012–2015, Texas Instruments Incorporated
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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 = 250 mA shown in this data sheet.
760
740
720
700
680
660
640
620
600
580
560
300
295
290
285
280
275
270
265
260
255
250
245
240
VIN = 10V
VIN = 12V
VIN = 14V
VIN = 16V
VIN = 10V
VIN = 12V
VIN = 14V
VIN = 16V
24
26
28
30
32
34
36
38
40
24
26
28
30
32
34
36
38
40
Output Voltage (V)
Output Voltage (V)
D001
D001
ILED = 0.15 A
RRT = 178 kΩ
ILED = 0.15 A
RRT = 499 kΩ
Figure 17. Switching Frequency vs Output Voltage
Figure 18. Switching Frequency vs Output Voltage
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8 Detailed Description
8.1 Overview
The LM3492HC device integrates a boost converter and a two-channel current regulator to implement a highly
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 device integrates an N-channel
MOSFET switch and a two-channel current regulator to minimize the component count and solution size.
The two-channel current regulator responds quickly to allow a very high contrast ratio of 10000:1. The two
channels dim individually. A digital command sent through the COMM pin disables Channel 1 of the current
regulator. 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.
When used in automotive LCD back-light panels, the device can operate efficiently for inputs as high as 65 V.
Diagnostic functions including power good indication, over-temperature indication, output current overvoltage and
undervoltage indications facilitate the interface of the device application circuit with external micro-processors
(MCUs). The device does not latch off and continues to operate in the presence of the indications. Other useful
features include thermal shutdown, VCC undervoltage lockout, and precision enable.
8.2 Functional Block Diagram
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8.3 Feature Description
8.3.1 Switching Frequency
The boost converter of the LM3492HC 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 19) 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 20 and
Figure 21. More switching frequency graphs can be found in the Typical Characteristics section.
600
950
560
850
520
750
480
650
550
450
350
250
150
440
400
360
320
280
240
200
100
200
300
400
500
600
700
800
6
8
10
12
14
16
18
20
22
24
26
RRT (kW)
Input Voltage (V)
D001
D001
ILED = 150 mA
VOUT = 30 V
VVIN = 12 V
ILED = 150 mA
VOUT = 30 V
RRT = 274 kΩ
Figure 19. Switching Frequency vs RT Resistance
Figure 20. Switching Frequency vs Input Voltage
600
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 kΩ
VVIN = 12 V
Figure 21. Switching Frequency vs Output Voltage
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Feature Description (continued)
8.3.2 LDO Regulator
The LM3492HC 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 LM3492HC 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
shutdown, 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 22. 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.
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 22. 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 LM3492HC 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 23, 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.
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Feature Description (continued)
VCC
ILIM
RILIM
CVCC
GND
Figure 23. Programmable Current Limit
8.3.5 Thermal Protection
An internal thermal shutdown circuit provides thermal protection. The circuit activates at 165°C (typically) to
disable the LM3492HC 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 LM3492HC 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
.
Override the DHC functionality by adding internal pullup resistance or external pullup resistance by connecting
the CDHC and VCC pins with a resistor. Use a value of approximately 10 MΩ. In this case, the voltage of the
CDHC pin rises above 2.5 V, and the voltage of the FB pin rises until the voltage reaches the overvoltage
protection threshold. Because the pullup is weak, DHC override occurs only at a low contrast ratio (approximately
< 1%).
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 LM3492HC 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 10000:1. The finest pulse width of the dimming
signal for the DIM1 and DIM2 pins is 300 ns.
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Feature Description (continued)
The device sets the current of an LED string (ILED) from 50 mA to 250 mA by using an external resistor RIREF
connected between the IREF pin and ground. Figure 24 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 500 mA. In this case, connect the DIM1 and DIM2 pins
together.
250
200
150
100
50
250
200
150
100
50
0
0
5
10
Regulation Current Resistance (kΩ )
Figure 24. LED Current vs Current Reference Resistance
(RIREF
15
20
25
0
10
20
30
40
50
Current Regulator Input Voltage (V)
Figure 25. 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 25). 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 26. 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) = 2.88 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) x 2.88 V / VFB(nom)
(5)
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Feature Description (continued)
VOUT
FB
CFB
RFB1
GND
RFB2
Figure 26. Output Voltage Feedback Circuit
8.3.9 Overvoltage Protection
When VFB is higher than the FB pin overvoltage protection (OVP) threshold VFB-OVP (typically 2.76 V and
maximum 2.88 V), the on-period of the integrated MOSFET stop immediately, and the MOSFET keeps off until
VFB falls back below below 2.545 V (typical hysteresis 0.215 V).
An alternative method to implement OVP is to directly monitor VOUT instead of VFB. An external circuit as shown
in Figure 27 is required. Current is injected to the ILIM pin to drive the LM3492HC device to the current limit
mode once VOUT is higher than the avalanche voltage of the Zener diode DOVP plus 0.7 V, the typical voltage on
the ILIM pin. In this case, the device imporses a maximum limit on VOUT. However, at the maximum limit of VOUT
,
VFB must be higher than 2.25 V to avoid affecting the start-up of the device.
VOUT
DOVP
ILIM
Figure 27. External OVP Circuit
8.3.10 Bidirectional Communication Pin
The COMM pin of the LM3492HC 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 28 and Figure 29 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.
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Feature Description (continued)
Figure 28. Read from the COMM Pin
Figure 29. Write to the COMM Pin
8.3.10.1 Power-Good Indication
Upon start-up, the COMM pin reads low. The output voltage of the boost converter of the LM3492HC 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.
8.3.10.2 Overtemperature Indication
If the junction temperature of the LM3492HC 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.
8.3.10.3 Output Current Undervoltage Indication
The LM3492HC 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.
8.3.10.4 Switching Frequency Tuning
After power good, the switching frequency (fSW) of the LM3492HC 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.
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8.5 Programming
8.5.1 Output Current Overvoltage Indication
The LM3492HC 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
0001
IOUT1
IOUT2
IOUT1
IOUT2
Overvoltage
0011
0101
0111
Undervoltage
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 LM3492HC device is shutdown
the LM3492HC 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.
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
over-temperature 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 LM3492HC device.
Table 2. Channel Control Commands
COMMAND
fSW resume normal
BIT PATTERN
1111 0111 0111 0111
1111 0001 0001 0001
1111 0011 0011 0011
1111 0101 0101 0101
fSW tune down by 20%
fSW tune down by 40%
Channel 1 disable
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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 LM3429HC/-Q1 device is ideal for automotive and marine GPS display and applications that require a high
contrast ratio.
9.2 Typical Application
The following procedures are to design an LED driver using the LM3492HC/-Q1 device.
Figure 30. Typical Application Schematic
9.2.1 Design Requirements
The following procedures are to design an LED driver using the LM3492HC device with an input voltage ranged
from 10 V to 24 V, and two LED strings consists of 10 LEDs each with a forward voltage of 3 V for each LED
when running at 250 mA. The output power is 15 W. The switching frequency fSW is designed to be 300 kHz.
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 30 V, and the minimum voltage of the IOUTn pin (n = 1,
2) is 1.25 V when ILED is 250 mA. As a result, VOUT(nom) is 31.25 V. Design VOUT(max) to be 50 V. From Equation 5,
VFB(nom) is approximately 1.8 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 265.1 kΩ, and a standard resistor value of 261 kΩ
is selected. CFB is selected to be 10 pF as recommended.
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
(6)
Also,
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Typical Application (continued)
ton = (1 – VIN/VOUT) / fSW
L1 = (VIN x ton) / 2IIN
(7)
(8)
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 LM3492HC device are individually dimmable), IIN is minimum. From Equation 6 to Equation 8, it
can be calculated that IIN(MIN), ton, and L1 are 0.326 A, 0.77 µs, and 28.5 µH. However,, from Equation 6, IIN is
maximum when VIN is minimum, which is 10 V in this example, and the two LED strings are turned on together.
Hence IIN(max) is 1.56 A. Then, ILR is
ILR = (VIN x ton) / L1
(9)
From Equation 7, ton is 2.27 µs. From (9), ILR is 0.80 A. The steady-state peak inductor current IL1(PEAK) is
IL1(PEAK) = IL1 + ILR / 2
(10)
As a result, IL1(PEAK) is 1.96 A. A standard value of 27 µH is selected for L1, and its saturation current is larger
than 1.96 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 10. 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:
CCDHC x 2.25V
tSS
=
120 mA
(11)
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 19, if fSW is 300 kHz, RRT is selected to be 442 kΩ. From Figure 24, if ILED is 250 mA,
RIREF is selected to be 4.99 kΩ.
9.2.2.8 RCOMM
Because the COMM pin is open drain, a resistor RCOMM of 52.3 kΩ is used to connect the VCC and COMM pins
to act as a pullup function.
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Typical Application (continued)
9.2.3 Application Curve
ILED = 150 mA
VOUT = 30 V
VVIN = 12 V
Dimming frequency = 1 kHz
Trace 1 = VIOUT1 Trace 4 = channel 1 LED
Figure 31. PWM Dimming
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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 LM3492HC 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
LM3492HC 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
VCC
CVCC
VIN
VIN
SW
L1
PGND
D1
SW
PGND
DIM2
LED+
+
VOUT
RRT
GND
RT
DIM1/CLK
LGND
RCOMM
CFB RFB1
COUT
FB
COMM
IREF
RFB2
GND
IOUT2
IOUT1
RIREF
-
-
LED- (2)
LED- (1)
CDHC
CCDHC
THERMAL/POWER VIA
Figure 32. Layout Recommendation
22
版权 © 2012–2015, Texas Instruments Incorporated
LM3492HC-Q1, LM3492HC
www.ti.com.cn
ZHCSEC6B –MARCH 2012–REVISED OCTOBER 2015
12 器件和文档支持
12.1 相关链接
表 3 列出了快速访问链接。 范围包括技术文档、支持与社区资源、工具和软件，以及样片或购买的快速访问。
表 3. 相关链接
部件
产品文件夹
请单击此处
请单击此处
样片与购买
请单击此处
请单击此处
技术文档
请单击此处
请单击此处
工具与软件
请单击此处
请单击此处
支持与社区
请单击此处
请单击此处
LM3492HC
LM3492HC-Q1
12.2 社区资源
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.
12.3 商标
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
12.4 静电放电警告
这些装置包含有限的内置 ESD 保护。 存储或装卸时，应将导线一起截短或将装置放置于导电泡棉中，以防止 MOS 门极遭受静电损
伤。
12.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
13 机械、封装和可订购信息
以下页中包括机械、封装和可订购信息。 这些信息是针对指定器件可提供的最新数据。 这些数据会在无通知且不
对本文档进行修订的情况下发生改变。 欲获得该数据表的浏览器版本，请查阅左侧的导航栏。
版权 © 2012–2015, Texas Instruments Incorporated
23
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status Package Type Package Pins Package
Eco Plan
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
Samples
Drawing
Qty
(1)
(2)
(3)
(4/5)
(6)
LM3492HCMH/NOPB
LM3492HCMHX/NOPB
LM3492HCQMH/NOPB
LM3492HCQMHX/NOPB
ACTIVE
HTSSOP
HTSSOP
HTSSOP
HTSSOP
PWP
20
20
20
20
73
RoHS & Green
SN
Level-1-260C-UNLIM
Level-1-260C-UNLIM
Level-1-260C-UNLIM
Level-1-260C-UNLIM
-40 to 125
-40 to 125
-40 to 125
-40 to 125
LM3492
HCMH
ACTIVE
ACTIVE
ACTIVE
PWP
2500 RoHS & Green
73 RoHS & Green
2500 RoHS & Green
SN
SN
SN
LM3492
HCMH
PWP
LM3492
HCQMH
PWP
LM3492
HCQMH
(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) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.
(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 finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two
lines if the finish value exceeds the maximum column width.
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
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
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.
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
9-Apr-2022
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
SPQ
Reel
Reel
A0
B0
K0
P1
W
Pin1
Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant
(mm) W1 (mm)
LM3492HCMHX/NOPB HTSSOP PWP
LM3492HCQMHX/NOPB HTSSOP PWP
20
20
2500
2500
330.0
330.0
16.4
16.4
6.95
6.95
7.1
7.1
1.6
1.6
8.0
8.0
16.0
16.0
Q1
Q1
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
9-Apr-2022
*All dimensions are nominal
Device
Package Type Package Drawing Pins
SPQ
Length (mm) Width (mm) Height (mm)
LM3492HCMHX/NOPB
LM3492HCQMHX/NOPB
HTSSOP
HTSSOP
PWP
PWP
20
20
2500
2500
367.0
356.0
367.0
356.0
35.0
35.0
Pack Materials-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
9-Apr-2022
TUBE
*All dimensions are nominal
Device
Package Name Package Type
Pins
SPQ
L (mm)
W (mm)
T (µm)
B (mm)
LM3492HCMH/NOPB
LM3492HCQMH/NOPB
PWP
PWP
HTSSOP
HTSSOP
20
20
73
73
495
495
8
8
2514.6
2514.6
4.06
4.06
Pack Materials-Page 3
MECHANICAL DATA
PWP0020A
MXA20A (Rev C)
www.ti.com
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