自动量程转换电路设计

Design of Automatic Range-changing Circuit

介绍了双积分式 A/D转换器 CC1 44 3 3在宽范围电压测量中自动量程转换电路的设计及工作原理 .通过多路模拟开关与运放的组合设置了多个电压量程 ,应用 CC1 44 3 3的超欠量程信息控制双向移位寄存器的移位操作 ,获得了合适的量程标志 .通过量程标志对多路模拟开关及显示器小数点位置的控制 ,实现了量程的自动切换及表示 .应用辅助门电路及数据选择器解决了量程标志中边界问题及无效量程标志问题 .设计的电路具有测量电压范围宽、工作稳定可靠、显示直观等优点 .

The design and the work principle of automatic range-changing circuit of dual-integral A/D converting chip CC14433 in voltage measuring of wide range are introduced. By the combination of multi-way analog switch with operation, more voltage ranges are set up. This circuit uses the formation of over-range and under-range of chip CC14433 to control the shift operation of two-way shift register and get a right symbal of range. By range symbal controlling multi-way analog switch and the place of the decimal point of display device, the automatic change and representation of range is realized. Using gate circuit and data selector, the border problem and the ineffective range symbal problem in range symbal are solved. The designed circuit has the advantages of wide measuring voltage extent, steady and reliable work, audio-visual display, etc.