To provide a filter circuit provided with a flying capacitor, having steep attenuation characteristics, and varying a Q value further.
The filter circuit includes: the flying capacitor which maintains polarity when switching from an input terminal to an output terminal, and the polarity of which is reversed when switching from the output terminal to the input terminal; a first capacitor Ch1 that is provided in parallel with the flying capacitor, at the input terminal of the flying capacitor; and a second capacitor Ch2 that is provided in parallel with the flying capacitor, at the output terminal of the flying capacitor. The flying capacitor is switched from the input terminal to the output terminal with a delay of a predetermined time after the switching from the output terminal to the input terminal, and the flying capacitor is switched from the output terminal to the input terminal with a delay of a predetermined time after the switching from the input terminal to the output terminal.
COPYRIGHT: (C)2010,JPO&INPIT
YOSHIZAWA ATSUSHI
Tetsuo Kanamoto
Koji Hagiwara
Kazuki Matsumoto
Next Patent: FILTER CIRCUIT AND COMMUNICATION DEVICE