Filter circuit
AssigneesYozan Inc., Sharp Kabushiki Kaisha
InventorsGuoliang Shou, Sunao Takatori, Makoto Yamamoto
Life of this patent
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Abstract
A filter circuit that consumes very little electric power. The active filter is a linear inverter constructed by 1) an inverting amplifying portion composed of an odd number of MOS inverters serially connected, 2) a grounded capacitance connected between an output of the inverting amplifying portion and ground, 3) a balancing resistance having a pair of resistances for connecting an output of one of the MOS inverters, other than the last MOS inverter, to the supply voltage and the ground, respectively, and 4) a feedback impedance for connecting the output and input of the inverting amplifying portion. A coupling capacitance is connected to the input of the linear inverter and a plurality of filter circuits are connected to an input of the coupling capacitance.
Claims11
A filter circuit comprising:
- i) an input terminal;
- ii) an inverting amplifier consisting of an odd number of MOS inverters serially connected,
- iii) a grounded capacitance connected between an output of said inverting amplifier and ground,
- iv) a balancing resistance consisting of a pair of resistances that couple an output of one of said MOS inverters, other than a last one of said MOS inverters, to a supply voltage and ground, respectively,
- v) a feedback impedance coupled between said output of said inverting amplifier and an input of said inverting amplifier,
- vi) a coupling capacitance coupled to said input of said inverting amplifier, and
- vii) a plurality of filters coupled between an input of said coupling capacitance and said input terminal.
A filter circuit comprising:
- i) an input terminal,
- ii) a serial inverter consisting of an odd number of MOS inverters,
- iii) a feedback capacitor coupled between an output of said serial inverter and an input of said serial inverter,
- iv) a coupling capacitance coupled to said input of said serial inverter, and
- v) a plurality of filters coupled between an input of said coupling capacitance and said input terminal.
Dependencies are inferred from the claim text.