现代电子技术
現代電子技術
현대전자기술
MODERN ELECTRONICS TECHNIQUE
2014年
7期
157-159
,共3页
LED驱动%PWM调光%占空比%Verilog HDL
LED驅動%PWM調光%佔空比%Verilog HDL
LED구동%PWM조광%점공비%Verilog HDL
LED drive%PWM dimming%duty ratio%Verilog HDL
介绍了一种应用于多通道恒流LED驱动芯片的PWM调光功能的实现方案，通过脉宽调制来改变流过各个通道LED的平均电流，进而实现了LED的调光控制。该模块由128 b串行移位寄存器，8 b数据锁存器，8 b计数器，以及8 b PWM灰度比较器构成，输出具有256阶灰度调节功能的PWM控制信号。外部数据时钟采用25 MHz，内部振荡器采用1.2 MHz。整体功能由Verilog HDL语言编程实现。
介紹瞭一種應用于多通道恆流LED驅動芯片的PWM調光功能的實現方案，通過脈寬調製來改變流過各箇通道LED的平均電流，進而實現瞭LED的調光控製。該模塊由128 b串行移位寄存器，8 b數據鎖存器，8 b計數器，以及8 b PWM灰度比較器構成，輸齣具有256階灰度調節功能的PWM控製信號。外部數據時鐘採用25 MHz，內部振盪器採用1.2 MHz。整體功能由Verilog HDL語言編程實現。
개소료일충응용우다통도항류LED구동심편적PWM조광공능적실현방안，통과맥관조제래개변류과각개통도LED적평균전류，진이실현료LED적조광공제。해모괴유128 b천행이위기존기，8 b수거쇄존기，8 b계수기，이급8 b PWM회도비교기구성，수출구유256계회도조절공능적PWM공제신호。외부수거시종채용25 MHz，내부진탕기채용1.2 MHz。정체공능유Verilog HDL어언편정실현。
An implementation scheme of PWM dimming function for 16-channel LED driving chip is presented in this paper. The dimming control of LED is realized changing the duty ratio of the LED average current through all the channels′ LEDs by PWM method. The module is composed of 128-bit serial shifting register,8-bit data latch,8-bit counter and 8-bit PWM grey-level comparator to output a PWM control signal with 256-order grey dimming function. The external data clock frequency is 25 MHz. The internal oscillator frequency is 1.2 MHz. The overall function is implemented by programming with Verilog HDL language.
