提高单片机A/D转换分辨率的系统设计方法

摘要

The A/D converter embedded in the microcontrollers mostly 10-bit resolution,the resolution of outside enlarge higher resolution is needed in the application of high precision A/D converter,increase the hardware cost of the system.This paper introduces a simulated switch,integrated operational amplifier and a small amount of resistance in the MCU peripheral hardware circuit constituted by using the principle of successive approximation conversion,which will be increase the resolution of the single chip microcomputer A/D converter from 10 to 13 bits.%单片机中内置的A/D转换器的分辨率大多数为10位分辨率,在高精度的应用中需要外扩更高分辨率的A/D转换器,这将增加系统的硬件成本.该文介绍一种利用模拟开关、集成运放和少量电阻在单片机外围构成硬件电路,利用逐次逼近的转换原理,用以将单片机A/D转换器的分辨率从10位提高到13位.