DIGITAL FILTER DEVICE, PHASE DETECTION DEVICE, POSITION DETECTION DEVICE, AD CONVERSION DEVICE, ZERO CROSS DETECTION DEVICE, AND DIGITAL FILTER PROGRAM

摘要

Provided is a digital filter device capable of removing the affect of noise such as chattering from a signal performing zero cross. The digital filter device (4) filters a binary digital signal (DIN) and outputs a binary digital signal (DOUT). The digital filter device (4) includes: a toggle flip-flop (12) which switches the signal level of the digital signal (DOUT) each time a trigger signal is inputted; an XOR circuit (13) which outputs a first enable signal (EN1) while the signal level of the digital signal (DIN) does not coincide with the signal level of the output digital signal (DOUT); and a charge counter (14) which performs counting in synchronization with a clock signal (CLK) while the first enable signal (EN1) is outputted. When the count value has reached an upper limit value, the charge counter (14) resets the count value to an initial value and outputs a carry on signal (ON_RCO) as the trigger signal to the toggle flip-flop (12).