| 摘要 |
PROBLEM TO BE SOLVED: To provide a filter circuit improved in the NF of a Gm-C filter. SOLUTION: The filter circuit comprises a filter section composed of at least one or more of first transconductance amplifiers each having mutual conductance changing in response to a first control signal and of a first capacitor; a second transconductance amplifier controlled in mutual conductance by the first control signal; a third transconductance amplifier controlled in mutual conductance by a second control signal; and a second capacitor connected with outputs of the first and second transconductance amplifiers and with an input of the filter section. COPYRIGHT: (C)2007,JPO&INPIT
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