摘要
文章提供了一种置换式分级并行 ADC新思路 ,它由分级电阻链和一个 m位的基本Flash ADC组成 ,可以实现转换速度快、分辨率高、器件少的目的。第一级转换时 ,由基本Flash ADC直接将待测模拟电压转换成 m位的数字量 ,并确定第一级等压电阻 ;第二级转换时 ,通过多路开关的连接 ,将一级电阻链的上部分和下部分合成一级电阻链的整体 ,由基本电阻链等价置换第一级等压电阻 ,然后由基本 Flash ADC将待测模拟电压直接转换 ,得到第二级 m位的数字量 ,同时还确定第二级等压电阻 ;依次类推 ,可以得到多级 m位的数字量。
It gives a new thinking of replacement grading type of Flash ADC, it could realize a requirement of fast speed conversion, high resolution, fewer devices to be used. It is composed by graded resistance chains and an m bits basic Flash ADC. When the first grade converting, the basic Flash ADC directly converts an analog voltage to be measured to an m bits digital value, and it confirms a voltageequivalent resistance of the first grade; While the second grade converting, through a multipleswitch linkage, to let the upper and lower parts of the first resistance chain combine to an entirety first resistance chain, and it is equivalent replaced the first voltageequivalent resistance by the basic resistance chain, then through the basic Flash ADC to convert directly the analog voltage to be measured. Then it could get an m bits digital value of the second grade, in the meantime it could confirm the voltageequivalent resistance of the second grade. By the same steps, it could get m bits digital values of multigrades.
出处
《电脑与信息技术》
2005年第1期1-3,42,共4页
Computer and Information Technology
