参数资料
型号: LM2794TLX
厂商: National Semiconductor
文件页数: 17/23页
文件大小: 0K
描述: IC LED DRVR WHT BCKLT 14USMD
RoHS指令信息: LM2794TLX Material
标准包装: 3,000
恒定电流:
拓扑: PWM,切换式电容器(充电泵)
输出数: 4
内部驱动器:
类型 - 主要: 背光
类型 - 次要: 白色 LED
频率: 325kHz ~ 675kHz
电源电压: 2.7 V ~ 5.5 V
输出电压: 3.8V
安装类型: 表面贴装
封装/外壳: 14-WFBGA
供应商设备封装: 14-TuSMD
包装: 带卷 (TR)
工作温度: -30°C ~ 85°C
其它名称: *LM2794TLX
SNVS168L – JANUARY 2002 – REVISED MAY 2013
POWER DISSIPATION
The power dissipation (P DISSIPATION ) and junction temperature (T J ) can be approximated with the equations
below. P IN is the power generated by the 1.5x charge pump, P LED is the power consumed by the LEDs, P POUT is
the power provided through the P OUT pin, T A is the ambient temperature, and θ JA is the junction-to-ambient
thermal resistance for the DSBGA package. V IN is the input voltage to the LM2794/5, V DX is the LED forward
voltage, I DX is the programmed LED current, and I POUT is the current drawn through P OUT .
P DISSIPATION = P IN - P LED ? P POUT
= [1.5×V IN ×(4I DX + I POUT )] ? (V DX ×4I DX ) ? (1.5×V IN ×I POUT )
T J = T A + (P DISSIPATION × θ JA )
(13)
(14)
(15)
The junction temperature rating takes precedence over the ambient temperature rating. The LM2794/5 may be
operated outside the ambient temperature rating, so long as the junction temperature of the device does not
exceed the maximum operating rating of 100°C. The maximum ambient temperature rating must be derated in
applications where high power dissipation and/or poor thermal resistance causes the junction temperature to
exceed 100°C.
DSBGA MOUNTING
The LM2794/5 is a 14-bump DSBGA with a bump size of 300 micron diameter. The DSBGA package requires
specific mounting techniques detailed in Application Note (AN -1112 SNVA009 ). NSMD (non-solder mask
defined) layout pattern is recommended over the SMD (solder mask defined) since the NSMD requires larger
solder mask openings over the pad size as opposed to the SMD. This reduces stress on the PCB and prevents
possible cracking at the solder joint. For best results during assembly, alignment ordinals on the PC board should
be used to facilitate placement of the DSBGA device. DSBGA is a wafer level chip size package, which means
the dimensions of the package are equal to the die size. As such, the DSBGA package lacks the plastic
encapsulation characteristics of the larger devices and is sensitive to direct exposure to light sources such as
infrared, halogen, and sun light. The wavelengths of these light sources may cause unpredictable operation.
Copyright ? 2002–2013, Texas Instruments Incorporated
Product Folder Links: LM2794 LM2795
17
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相关代理商/技术参数
参数描述
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LM2795 制造商:未知厂家 制造商全称:未知厂家 功能描述:
LM27951 制造商:NSC 制造商全称:National Semiconductor 功能描述:White LED Adaptive 1.5X/1X Switched Capacitor Current Driver
LM27951SD 功能描述:LED照明驱动器 RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
LM27951SD/NOPB 功能描述:LED照明驱动器 RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N