建设系统的干部学习先进典型立足本职扎实工作心得体会

on semi公司的 ncv7680是线性稳流及控制器，包含8个线性可编程恒流源，能支持高达每通道75 ma的发光二极管(led)驱动电流。设计用于汽车固态组合尾灯(rcl)的稳流和控制，支持两个亮度等级，一个用于停车，另一个用于尾部照明。

典型应用包括组合尾灯、日间行车灯(drl)、雾灯、中央高位停车灯(chmsl)阵列、转向信号灯和液晶显示器(lcd)背光。本文介绍了ncv7680主要特性，方框图，升压模式和多种应用电路，以及ncv7680-ncv3163评估板主要特性，电路图和材料清单（bom）。

the ncv7680 consists of eight linear programmable constant current sources. the part is designed for use in the regulation and control of led based rear combination lamps for automotive applications. system design with the ncv7680 allows for two brightness levels, one for stop and one for tail illumination, or optional pwm control can also be implemented. discrete led brightness levels are easily programmed (stop current value, tail duty cycle value) optional external ballast fet allows for power distribution on designs requiring high currents. set back power limit reduces the drive current during overvoltage conditions. this is most useful for low current applications when no external fet is used.ncv7680主要特性：constant current outputs for led string drive led drive current up to 75ma per channel open led string diagnostic with open-drain output slew rate control low dropout operation external modulation capable on-chip 1 khz tail pwm dimmingstop current set point programmability tail dimming set point programmabilityovervoltage set back power limitationpb-freencv7680优势:led devices are best controlled with current drive due to their exponential voltage characteristicssufficient drive for most popular low current led devicessystem functionality back to the microprocessoreliminates emi concernsmaintains functionality during drops in automotive battery voltageflexible for many system operation setupssimplifies system design.easy programmability with one resistoreasy programmabil