程控放大器的设计与实现摘 要本文介绍了一种可通过程序改变增益的放大器。它与 ADC 相配合,可以自动适应大范围变化的模拟信号电平。系统以 89S51 单片机作微处理器,运用NE5532 芯片组成运放电路,采纳 CD4052 芯片担任增益切换开关,通过软件控制开关的闭合或断开来达到改变电路的增益.文章首先对系统方案进行论证,然后对硬件电路和软件设计进行了说明,最后重点阐述了系统的调试过程,并且对调试过程中遇到的问题以及解决方案进行了详细说明.该系统设计达到了预期要求,实现了最大放大 60db 的目的。关键词程控放大器;运算器放大器;单片机;增益The Design and Realization of Program-Controll AmplifierAbstractThis article introduces a amplifier which changes the gain through the software。 It coordinates with ADC and adapts the simulated signal level with wide range change automatically. The system uses the 89s51 SCM as the core 。 The NE5532 chip composes the operational circuit and the CD4052 chip composes the gain switch。 The gain of the circuit is changed by software which can control switch closed or disconnect.The article first demonstrates the system plan, then introduces the hardware and the software, finally explains the debugging process of the system with emphasis。 It also especially analogizes the problem in the debugging process and the resolutions 。 This system design has achieved anticipative request and realized enlarged 60db most greatly the goal.Key wordsProgram—controlled amplifier; operational Amplifier; SCM; gain前言在计算机数控系统中,模拟信号在送入计算机进行处理前,必须进行量化,即进行A/D 转换[ 1 ]。进行A/D 转换之前,必须考虑A/D 转换器的分辨率和模拟输入电压量程这两个问题。在一些特别的应用中,我们常希望输入信号的幅值接近A/D 的输入电压量程的上限.工程上常实行改变放大器增益的方法对幅值大小不一的信号进行放大。在计算机数控系统中,为实现不同幅度信号的放大, 往往不希望、甚至也不可能利用手动方法来实现增益变换。利用程控放大器可以很好地解决上述...