摘要
针对传统的RC移相电路存在误差大、参数固定后移相角度不易调节的问题,提出一种以单片机为主控、CPLD为核心的高精度程控移相器。单片机接收键盘输入的移相指令,计算处理后,通过总线将移相值发送至CPLD,CPLD利用分频、移位寄存、数据选择等实体电路实现移相。仿真波形和实际电路测试均表明,设计的移相器输出波形无失真、移相范围宽、精度高、可步进,步进的最小值可通过改变移位寄存器的时钟频率调节。可应用于锁定放大、正交调制等领域。
Due to the existence of big errors of traditional RC phase-shift circuits and the difficulty in adjusting phase shifting angle after getting fixed RC parameters, a type of high accuracy phase shifter using single chip microcomputer as controller and centring on CPLD, is designed by taking full advantage of high accuracy CPLD in sequential circuits. The single chip microcomputer receives a phase shift instruction which is entered using a keyboard. After that, the instruction can be processed by the microcomputer and delivered to CPLD via the interface bus. Then CPLD can realize the phase shift by using frequency dividers, shift registers and data selector. The simulation waveform and the actual circuit testing show that that the output waveform is undistorted and shift of phase is extremely precise. And the minimum step can be changed by the frequency of the clock of shift registers. The designed circuit provides a flexible and high-accuracy phase shifter for lock-in amplifiers and quadrature amplitude modulation circuits.
出处
《电子测量技术》
2014年第12期5-9,共5页
Electronic Measurement Technology
基金
江苏省产学研联合创新资金-前瞻性联合研究(BY2011112)
江苏省普通高校研究生科研创新计划(CXLX12_0508)
江苏省高等学校大学生创新创业训练计划(201410300048Z)项目
关键词
锁定放大器
移相器
程控
CPLD
lock-in amplifiers
phase shifters
program controlled
CPLD
