Apple-Ⅱ微机—色谱仪联机数据处理的16位A/D转换电路

The 16 Bit A/D Conversion Circuit for Online Data Processing of Apple-ⅡMicro-computer with Colout Spectrometer

本文介绍的16位A/D 转换电路,是专为Apple-Ⅱ与色谱仪联机数据处理而设计的.电路采用两片8位的D/A 芯片,用EPROM 替代转换中的逐位逼近寄存器,实现16位A/D 转换,并采用A/D 转换量程扩充处理方法,使该电路在处于小信号输入状态下的转换分辩率达到20位字长.

This paper presents the 16 bit A/D conve-rsion circuit specifically designed for On-line data processing of Apple-Ⅱ with colourspectrometer.The circuit is eguipped with acouple of 8 bit D/A conversion,with EPROMin place of the cascade approach register,so as to make the 16 bit A/D conversion.Thefloating point processing method of A/Dconversion is adopted,with the result that,at a small signal input state,it can make itsconversion accuracy to 20 bit.