ATE460691T1 - METHOD AND DEVICE FOR HIGHLY ACCURATE DIGITAL MEASUREMENT OF AN ANALOG SIGNAL - Google Patents

Abstract

The invention relates to a method for the highly accurate digital measurement of an analogue signal and to a corresponding device. A measuring clock pulse (f<SUB>M</SUB>) is generated from a clock pulse signal (f<SUB>T</SUB>). In a first calibration step, a capacitor (C) is charged with a constant current (I<SUB>K</SUB>) during the entire period of the clock pulse signal (f<SUB>T</SUB>). The charge voltage is maintained and is converted into a digital comparison number. In a subsequent measuring step, a first portion (T<SUB>1</SUB>) of the duration of the analogue signal is determined as an appropriately selected, whole-numbered multiple (m) of the duration (T<SUB>0</SUB>) of the period of the clock pulse signal (f<SUB>T</SUB>). The capacitor (C) is charged with the same constant current (I<SUB>K</SUB>) from the end of the first portion (T<SUB>1</SUB>) until the occurrence on the specified flank of the received signal (f<SUB>E</SUB>). The charge voltage is maintained and converted into a digital measuring number. The measuring number is divided by the comparison number, which permits the duration of a second portion (T<SUB>2</SUB>) of the analogue signal to be calculated as a fraction of a measuring clock pulse period. The measured value of the analogue signal is calculated from the first portion (T<SUB>1</SUB>) and the second portion (T<SUB>2</SUB>).