Battery Operated Auto Ranging DVM
Related Page - Battery Operated Auto Ranging DVM with the ICL7106
This application note describes a technique for auto-ranging a battery operated DVM suitable for panel meter applications. Also, circuit ideas will be presented for conductance and resistance measurement, 9V battery and 5V supply operations, and current measurement.
The control signals necessary for auto-ranging are over-range, under-range, and clock. The over-range and under-range inputs control the direction of a scale shift, becoming active at the completion of an invalid conversion and remaining active until a valid conversion occurs. The clock input controls the timing of a scale shift. This signal should occur only once per conversion cycle, during a time window which will not upset an ongoing conversion and must be disabled after valid conversions