参数资料
型号: LM3445MX/NOPB
厂商: National Semiconductor
文件页数: 8/40页
文件大小: 0K
描述: IC LED DRIVER TRIAC DIMM 14SOIC
标准包装: 2,500
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: 14-SOIC(0.154",3.90mm 宽)
供应商设备封装: 14-SOICN
包装: 带卷 (TR)
工作温度: -40°C ~ 125°C
其它名称: LM3445MX
SNVS570L – JANUARY 2009 – REVISED MAY 2013
An RC network consisting of R1, R2, and C1 delay the turn on of the triac until the voltage on C1 reaches the
trigger voltage of the diac. Increasing the resistance of the potentiometer (wiper moving downward) increases the
turn-on delay which decreases the on-time or "conduction angle" of the triac ( θ ). This reduces the average power
delivered to the load. Voltage waveforms for a simple triac dimmer are shown in Figure 13 . Figure 13 a shows the
full sinusoid of the input voltage. Even when set to full brightness, few dimmers will provide 100% on-time, i.e.,
the full sinusoid.
(a)
(b)
DELAY
?
?
DELAY
(c)
Figure 13. Line Voltage and Dimming Waveforms
Figure 13 b shows a theoretical waveform from a dimmer. The on-time is often referred to as the "conduction
angle" and may be stated in degrees or radians. The off-time represents the delay caused by the RC circuit
feeding the triac. The off-time be referred to as the "firing angle" and is simply 180° - θ .
Figure 13 c shows a waveform from a so-called reverse phase dimmer, sometimes referred to as an electronic
dimmer. These typically are more expensive, microcontroller based dimmers that use switching elements other
than triacs. Note that the conduction starts from the zero-crossing, and terminates some time later. This method
of control reduces the noise spike at the transition.
Since the LM3445 has been designed to assess the relative on-time and control the LED current accordingly,
most phase-control dimmers, both forward and reverse phase, may be used with success.
8
Product Folder Links: LM3445
Copyright ? 2009–2013, Texas Instruments Incorporated
相关PDF资料
PDF描述
NPS 2-T126 0.500 OHM 1% RES .5 OHM 25W 1% DPAK
REC3-4815SRW/H4/A/M CONV DC/DC 3W 36-72VIN 15VOUT
P51-1500-S-S-D-5V-000-000 SENSOR 1500PSIS 1/4 NPT 5V
P51-500-S-E-D-4.5OVP-000-000 SENSOR 500PSI 3/8-24 UNF .5-4.5V
RMW-140/42-1200/ADH-0 HEAT SHRINK TUBING
相关代理商/技术参数
参数描述
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
LM3447-A19-120VEVM 功能描述:LED 照明开发工具 LM3447 Eval Mod RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装:
LM3447-A19-230VEVM 功能描述:LED 照明开发工具 LM3447 Eval Mod RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装: