电压频率转换器设计与实现毕业论文.doc

本科生毕业论文(设计) 题 目： 电压频率转换器设计与实现 学生姓名： 丁 维 学 号： 201011030123 专业班级： 自动化10101班 指导教师： 齐 庭 庭 完成时间： 2014年5月10日 PAGE PAGE 2 摘 要 电压频率转换器VFC（Voltage?Frequency?Converter）是一种实现模数转换功能的器件，将模拟电压量变换为脉冲信号，该输出脉冲信号的频率与输入电压的大小成正比。电压频率转换器也称为电压控制振荡电路（VCO），简称压控振荡电路。随电压—频率转换实际上是一种模拟量和数字量之间的转换技术。当模拟信号（电压或电流）转换为数字信号时，转换器的输出是一串频率正比于模拟信号幅值的矩形波，显然数据是串行的。这与目前通用的模数转换器并行输出不同，然而其分辨率却可以很高。串行输出的模数转换在数字控制系统中很有用，它可以把模拟量误差信号变成与之成正比的脉冲信号，以驱动步进式伺服机构用来精密控制。 设计高精度电压转换器，可以利用LM324运算放大器与555定时器为核心器件的高精度线性电压频率转换器。整个电路主要是由稳定电压源模块、信号输入模块、恒流源模块、输入信号变换模块、以555定时器为核心的压频转换模块等5个模块组成的。本设计方案温漂小、抗干扰能力强、价格便宜、线性度较好、而且变换精度高。 关键词：555定时器；线性；电压频率转 PAGE PAGE 2 Abstract Voltage Frequency Converter VFC (Voltage Frequency Converter) is a kind of realizing the function of analog-to-digital conversion device, analog Voltage transform into pulse signal, the output pulse signal Frequency proportional to the size of the input Voltage. Voltage frequency converter is also known as voltage control oscillation (VCO) circuits, referred to as voltage-controlled oscillation circuit. Over voltage, frequency conversion, in fact, a kind of conversion between analog and digital technology. When analog signals (voltage or current) is converted to a digital signal, the output of the converter is a string of frequency is proportional to the analog signal amplitude of the rectangular wave, obviously is the serial data. This AD converter with the general parallel output is different, but its resolution can be very high. Serial output of the adc is useful in the digital control system, it can make analog error signal proportional to the pulse signal, to drive the stepping servo mechanism used for precise control. Design of high precision voltage converter, can use LM324 operational amplifier with 555 timer as the core device of high precision linear voltage frequency converter. The whole