基于FPGA的高速脉冲恒流控制系统的设计

Design of High-Speed Pulse Constant Current Control System Based on FPGA

结温是表征发光二极管品质和寿命的一个关键因素,针对电致发光光谱检测法测量LED芯片结温需要脉冲电流精确可控的突出问题,以Xilinx XC3S400 FPGA为核心,设计并开发了一套高速度、高精度的脉冲恒流控制系统。该系统根据从PC接收的数据精确控制LED上脉冲电流大小、脉冲周期、脉冲宽度,同时在保证脉冲电流的升降时间小于5μ～s的情况下将过冲控制在5%内,以避免因冲击电流过大而损坏LED,为非接触式测量LED灯具中芯片结温提供了极大的方便。该系统稳定可靠,效果良好。

A high-speed and high-precision pulse constant current control system based on Xilinx XC3S400 FPGA for the purpose of junction temperature（JT） measurement is designed and developed,which is a key parameter of the performance and lifetime of light emitting diodes（LEDs）.According to the data received from the PC,the system is precise in controlling the value,period and width of the pulse current following through the LEDs.And the pulse constant current control system can control the overshoot in 5% when ensuring the rise and fall time less than 5 μs to avoid damaging the LEDs due to the too large impact current.This system is reliable and effective in non-contact measurement of JTs of LEDs.