双积分A/D转换器的量程自动转换

Automatic Range Switching of a Dual Integration A/D convertor

介绍了一种双积分式 A/ D转换器在宽范围量程测量中的自动量程转换技术。在测量仪表的输入通道中 ,用计数器对双积分型 A/ D转换器本身所固有的过量程 /欠量程信号计数 ,计数器的输出作为量程编码去控制量程的选择 ,同时又是送到 CPU的量程指示信号。该技术扩大了 A/ D转换量程 ,提高了精度 ,设计简单 ,工作可靠。

This paper introduces an automatic range switching technique for a dual integration A/D convertor in wide range measurement. In the input channel of the measuring instrument a counter is used to count the inherent over range/short of range signals of the dual integration A/D convertor. The output of the convertor is used as the range code to control the selection of range; at the same time it serves as the range indication signal for CPU. This technique extends the switched range of A/D convertor and features high accuracy,simple design and reliability.