| 摘要 |
PROBLEM TO BE SOLVED: To provide an active filter (band-pass filter) which is small in circuit scale and is hardly influenced by the output impedance of a preceding stage circuit. SOLUTION: An active filter is composed of a first transconductor 1, equipped with a non-inverting input terminal grounded in terms of the viewpoint of an alternating current and an inverting input terminal where an output signal vo is applied; a first capacitor C1, whose one end is connected to the output terminal of the transconductor and other end is grounded in terms of an alternating current; a second transconductor 2 equipped with a non-inverting input terminal where the output of the first transconductor 1 is supplied and an inverting input terminal grounded in terms of the viewpoint of an alternating current; a second capacitor C2 whose one end is connected to the output terminal of the transconductor 2 and other end is grounded in terms of an alternating current; and a third transconductor 3, which is equipped with a non-inverting input terminal where input signals vin are inputted and an inverting input terminal and an output terminal which are connected together and supplies output signals vo, together with the output of the transconductor 2.
|
