您现在的位置:首页 > 案例分析案例分析

基于LT3956设计的80V恒流恒压HBLED驱动技术

发布时间:2014-12-10 08:52:48  来源:大电流电感厂家   查看:
LT3956 是80V输入80V输出恒流恒压DC/DC转换器,非常适合用来驱动大电流高亮度LED(HBLED).3000:1真彩色PWM调光,输入电压从4.5V到80V,输出电压高达80V,内部集成了3.3V/80V开关,可调频率从100kHz到1MHz,能以升压,降压,升降压,SEPIC或反激模式驱动LED,主要用于大功率LED,电池充电器和精密电流限压稳压器.本文介绍了LT3956主要特性,方框图,以及多种应用电路,包括效率95%25W WLED汽车头灯驱动电路图, 升-降压模式LED驱动电路图, 超大电容充电电路图,以及降压模式90W LED驱动电路图等.

80VIN, 80VOUT Constant-Current,Constant-Voltage Converter

The LT®3956 is a DC/DC converter designed to operate as a constant-current source and constant-voltage regulator. I模压电感t is ideally suited for driving high current LEDs. It features an internal low side N-channel power MOSFET rated for 84V at 3.3A and driven from an internal regulated 7.15V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages. A ground referenced voltage FB pin serves as the input for several LED protection features, and also makes it possible for the converter to operate as a constant-voltage source. A frequency adjust pin allows the user to program the fre电感厂家quency from 100kHz to 1MHz to optimize efficiency, performance or external component size.

The LT3956 senses output current at the high side of the LED string. High side current sensing is the most flexible scheme for driving LEDs, allowing boost, buck mode or buck-boost mode configuration. The PWM input provides LED dimming ra大电流电感tios of up to 3000:1, and the CTRL input provides additional analog dimming capability.

LT3956主要特性:

3000:1 True Color PWMTM Dimming

Wide Input Voltage Range: 4.5V to 80V

Output Voltage Up to 80V

Internal 3.3A/84V Switch

Constant-Current and Constant-Voltage Regulation

250mV High Side Current Sense

Drives LEDs in Boos变压器与电感器设计手册t, Buck Mode, Buck-Boost Mode, SEPIC or Flyback Topology

Adjustable Frequency: 100kHz to 1MHz

Open LED Protection

Programmable Undervoltage Lockout with Hysteresis

Constant-Voltage Loop Status Pin

PWM Disconnect Switch Driver

CTRL Pin Adjusts High Side Current Sense Threshold

Low Shutdown Current: <1μA

Programmable Soft-Start

Available in the 36-Lead (5mm × 6mm) QFN Package

LT3956应用:

High Power LED

Battery Charger

Accurate Current Limited Voltage Regulator

图1. LT3956方框图

图2. LT3956效率95%25W WLED汽车头灯驱动电路图

图3. LT3956升-降压模式LED驱动电路图

图4. LT3956超大电容充电电路图

图5. LT3956效率90% 20W SPEIC LED驱动电路图

图6. LT3956降压模式90W LED驱动电路图 平面变压器厂家 | 平面电感厂家

[逆变器]请各位推荐比IRF3205 VDS稍高一些的功逆变器用TL494,IRF3205推挽驱动,开关管关闭时尖峰击穿功率管:使用12V供电的逆变,当供电到达14V,关闭瞬间,尖峰比较高,发热严重,最后烧管,怀疑是尖峰击穿所致,所以想用VDS高些的功率管来解决问题,请教各位有哪些规格型号推荐,谢谢~!满意回复+17PowerAnts 查看完整内容IR都被英飞凌收购了,你用上面这些英飞凌“牛管”吧,价格还行,需要样片的话

视频监控系统中ARM与DSP的HPI接口设计摘要:本文介绍了ARMS3C44B0X与DSPTMS320DM642的主要特点以及HPI接口的原理,提出了一个采用HPI设计ARM与DSP通信接口的方案,该方案应用在基于ARM与DSP的嵌入式视频监控

基于DSP的机载光电稳瞄稳定环路数字控制实现1、引言 机载光电稳瞄产品大量装备于各种类型飞机上,其核心是陀螺稳定平台,主要作用在于隔离载体的角扰动,使安装在载体上的光学传感器的视轴在惯性空间内保持稳定,使光学传感器得到清晰的图像。稳定控制最直观

CopyRight2014
大电流电感 | 大功率电感 | 扁平线圈电感 注塑加工厂