参数资料
型号: LM3445MMX/NOPB
厂商: National Semiconductor
文件页数: 15/40页
文件大小: 0K
描述: IC LED DRIVER TRIAC DIMM 10-MSOP
应用说明: LM3445 Reference Design
标准包装: 3,500
系列: PowerWise®
恒定电流:
拓扑: PWM,降压(降压)
输出数: 1
内部驱动器:
类型 - 次要: 高亮度 LED(HBLED)
频率: 30kHz ~ 1MHz
电源电压: 8 V ~ 12 V
安装类型: 表面贴装
封装/外壳: 10-TFSOP,10-MSOP(0.118",3.00mm 宽)
供应商设备封装: 10-MSOP
包装: 带卷 (TR)
工作温度: -40°C ~ 125°C
配用: LM3445-220VEVAL-ND - BOARD EVAL LM3445 220V
LM3445-120VSMEV-ND - BOARD EVAL LM3445 110V
LM3445TRIACEVAL-ND - BOARD EVAL LM3445MM
其它名称: LM3445MMX
LM3445MM
D10
C12
V BUCK
L2
SNVS570L – JANUARY 2009 – REVISED MAY 2013
R4
Q3
I COLL
GATE
8
Q2
4
COFF
ISNS
7
R3
GND
6
C11
Figure 21. LM3445 Buck Regulation Circuit
OVERVIEW OF CONSTANT OFF-TIME CONTROL
A buck converter’s conversion ratio is defined as:
V IN = D = t ON + t OFF = t ON x f SW
V O t ON
(3)
Constant off-time control architecture operates by simply defining the off-time and allowing the on-time, and
therefore the switching frequency, to vary as either V IN or V O changes. The output voltage is equal to the LED
string voltage (V LED ), and should not change significantly for a given application. The input voltage or V BUCK in
this analysis will vary as the input line varies. The length of the on-time is determined by the sensed inductor
current through a resistor to a voltage reference at a comparator. During the on-time, denoted by t ON , MOSFET
switch Q2 is on causing the inductor current to increase. During the on-time, current flows from V BUCK , through
the LEDs, through L2, Q2, and finally through R3 to ground. At some point in time, the inductor current reaches a
maximum (I L2-PK ) determined by the voltage sensed at R3 and the ISNS pin. This sensed voltage across R3 is
compared against the voltage of dim decoder output, FLTR2, at which point Q2 is turned off by the controller.
Copyright ? 2009–2013, Texas Instruments Incorporated
Product Folder Links: LM3445
15
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参数描述
LM3445MX 制造商:NSC 制造商全称:National Semiconductor 功能描述:Triac Dimmable Offline LED Driver
LM3445MX/NOPB 功能描述:板上安装温度传感器 RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
LM3445TRIACEVAL 功能描述:BOARD EVAL LM3445MM RoHS:否 类别:编程器,开发系统 >> 过时/停产零件编号 系列:PowerWise® 标准包装:1 系列:- 传感器类型:CMOS 成像,彩色(RGB) 传感范围:WVGA 接口:I²C 灵敏度:60 fps 电源电压:5.7 V ~ 6.3 V 嵌入式:否 已供物品:成像器板 已用 IC / 零件:KAC-00401 相关产品:4H2099-ND - SENSOR IMAGE WVGA COLOR 48-PQFP4H2094-ND - SENSOR IMAGE WVGA MONO 48-PQFP
LM3445TRIACEVAL/NOPB 制造商:Texas Instruments 功能描述:TRIAC Dimmable Offline LED Driver Evaluation Board
LM3447 制造商:TI 制造商全称:Texas Instruments 功能描述:Phase Dimmable, Primary Side Power Regulated PFC Flyback Controller for LED Lighting