Auswertung eines Puls-Weiten-Modulations-Signals

摘要

The invention relates to a method for evaluating a pulse-width modulation signal (PWM signal) which has a first level (H) and a second level (L), wherein a countup occurs for the duration of the first level (H), at least periodically, at a predetermined frequency (F1). The invention is characterised in that for the duration of the second level (L) a countdown occurs, at least periodically. A circuit arrangement for evaluating the PWM signal has a first counter (1), said first counter having a first activation input (E). A first activation signal (SE) is connected to the first activation input. The activation signal (SE) is formed from the PWM signal. The first counter (1) only counts whilst it is being activated by the first activation signal (SE). The first counter (1) has a first counting direction input (U/D), to which a first counting direction signal is connected, said counting direction signal adopting two states (H, L). The first counter (1) counts upwards when the first counting signal is in its first state (H), and counts downwards when said first counting signal is in its second state (L).