METHOD AND DEVICE FOR THE HIGHLY ACCURATE DIGITAL MEASUREMENT OF AN ANALOGUE SIGNAL

摘要

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 (fSUBM/SUB) is generated from a clock pulse signal (fSUBT/SUB). In a first calibration step, a capacitor (C) is charged with a constant current (ISUBK/SUB) during the entire period of the clock pulse signal (fSUBT/SUB). The charge voltage is maintained and is converted into a digital comparison number. In a subsequent measuring step, a first portion (TSUB1/SUB) of the duration of the analogue signal is determined as an appropriately selected, whole-numbered multiple (m) of the duration (TSUB0/SUB) of the period of the clock pulse signal (fSUBT/SUB). The capacitor (C) is charged with the same constant current (ISUBK/SUB) from the end of the first portion (TSUB1/SUB) until the occurrence on the specified flank of the received signal (fSUBE/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 (TSUB2/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 (TSUB1/SUB) and the second portion (TSUB2/SUB).