AD 轉換是測量中一個非常重要的部分，為了達到精度比較高的轉換效果，人們往往選擇位數較高的AD 轉換器，這樣容易造成電路的成本過高。本文就介紹一種如何利
用普通的AD 轉換器來實現高精度的AD 轉換，它利用兩次采樣的原理，通過一個模擬量進行兩次轉換，從而實現高精度。此轉換器所需元件比較簡單，主要由一個凌陽SPCE061A單片機和一些普通的選通、運放電路組成，文章從硬件電路的組成和軟件程序的編寫兩個方面來進行說明，清晰的介紹了如何來實現高精度轉換的功能。
【關鍵詞】 AD 轉換，高精度，兩次采樣，原理
【ABSTRACT】In the scopes of measure, AD conversion is a very important part, the higher bit AD converter always is chosen in order to gain high precision, but it is very expensive for the circuit . With twice sampling theory, an analog voltage is converted twice to realize the high precision. The converter is composed of lingyang SPCE061A mcu, ordinary gates and amplifiers, it is simple. That how to realize the high precision conversion is showed clearly on hardware circuit and software programs in this article.
【KEYWORDS】 AD conversion, high precision, twice sample, elements