Linear LT3965八开关矩阵LED调光器系统方案

Linear公司的LT3965是八开关矩阵LED调光器,具有八个单独控制的17V/330mΩ NMOS开关,八个开关可并联/或串联,采用I2C串口和MCU通信,每个开关可单独开/关/调光1-4个LED,数字可编程256:1 PWM调光,主要用在汽车LED头灯,大型LED显示屏,自动照相机闪光设备,RGBW彩色混合照明.本文介绍了LT3965主要特性,框图和几种应用电路,以及演示板DC2218A特性,测试建立图,电路图,材料清单和PCB元件布局图.
The LT®3965 is an LED bypass switching device fordimming individual LEDs in a string using a commoncurrent source. It features eight individually controlledfloating source 17V/330mΩ NMOS switches. The eightswitches can be connected in parallel and/or in series tobypass current around one or more LEDs in a string. TheLT3965 uses the I2C serial interface to communicate withthe microcontroller. Each of the eight channels can beindependently programmed to bypass the LED string inconstant on or off,or PWM dimming with or without fadetransition. Using the fade option provides 11-bit resolution
logarithmic transition between PWM dimming states.
The LT3965 provides an internal clock generator and alsosupports external clock source for PWM dimming. TheLT3965 reports fault conditions for each channel such asopen LED and shorted LED. The four address select pinsallow 16 LT3965 devices to share the I2C bus. The deviceis available in a 28-lead TSSOP package.
LT3965主要特性:
Eight Independent 17V 330mΩ NMOS Switches
Independent On/Off/Dimming Control of 1 to 4 LEDsfor Each Switch
I2C Multidrop Serial Interface with ProgrammableOpen LED and Shorted LED Fault Reporting
16 Unique I2C Addresses
VDD Range: 2.7V to 5.5V and VIN Range: 8V to 60V
Digital Programmable 256:1 PWM Dimming
Fade Transition Between PWM Dimming States
Optional Internal Clock Generator or External ClockSource for PWM Dimming
Open LED Overvoltage Protection
Flicker Free PWM Dimming
LT3965应用:
Automotive LED Headlight Clusters
Large LED Displays
Automated Camera Flash Eq...