本文根据原码、补码、反码数的表示特点,研究出一种简便的原码、补码、反码D/A电路。将它们用于逐次逼近式A/D系统中时,可以构成原码、补码、反码系统的A/D变换器系统。本文还简要介绍了上述电路系统中用的一种重要电路:高精度模拟开关电路。这些电路与系统均已实际使用,证明是可行的。 In this paper, according to the original code, complement, inverse code representation, developed a simple original code, complement, anti-code D / A circuit. When they are used in successive approximation type A / D system, they can form the A / D converter system of the original code, the complement code and the anti-code system. This article also briefly describes an important circuit used in the above circuit system: high-precision analog switch circuit. These circuits and systems have been actually used, proved to be feasible.