Digitally Controlled Absolute Voltage Division

In this paper, a principle for absolute voltage division is presented. The division ratio of a voltage divider on this principle does not depend on the values of its elements but depends exclusively on the configuration of the divider network. Hence, calibration is not necessary and not even possible. Absolute voltage division is obtained by cyclically shifting the network elements along all positions in the divider network. Each position is maintained for an equally long time interval. The average output voltage of such a dynamic divider is identical to that of a static divider with the same network configuration but composed of elements which all have the same value. To verify the principle in practice, a digitally controlled resistive voltage divider has been built. It has been realized with easily available electronic components, such as carbon resistors with ± 5-percent tolerance, junction field-effect transistors as electronic switches and digital integrated circuits for the generation of the switch drive signals. The inaccuracy of this divider is less than 5 ×10-6 and the temperature coefficient of the division ratio is less than 5 × 10-8/°C from 0°C to 40°C. It is expected that the performance, of this prototype can be improved.