Transconductor, integrator, and filter circuit

A transconductor for receiving a differential voltage signal and outputting a differential current signal, comprising:

• a first transconductor and a second transconductor for receiving the differential voltage signal and outputting a single-end current signal,
• wherein an inversion input terminal of one of the first and second transconductors is connected with a non-inversion input terminal of the other,
• the transconductor outputs a current signal output from each of the first and second transconductors as the differential current signal, and
• the first and second transconductors each receive a plurality of differential voltage signals.

An integrator comprising:

• a transconductor for receiving a differential voltage signal and outputting a differential current signal, comprising:
• a first transconductor and a second transconductor for receiving the differential voltage signal and outputting a single-end current signal,
• wherein an inversion input terminal of one of the first and second transconductors is connected with a non-inversion input terminal of the other, and the transconductor outputs a current signal output from each of the first and second transconductors as the differential current signal,
• wherein the first and second transconductors each comprise:
• a first voltage-to-current conversion circuit and a second voltage-to-current conversion circuit for receiving a positive side and a negative side of the differential voltage signal, respectively;
• and
• a current mirror circuit having an input side and an output side to which the first and second voltage-to-current conversion circuits are connected, respectively,
• wherein the single-end current signal is output from a connection point between the second voltage-to-current conversion circuit and the current mirror circuit,
• said transconductor further comprising:
• a first variable current source and a second variable current source connected any one of the input side and the output side of the current mirror circuit in each of the first and second transconductors;
• and
• a common-mode feedback circuit for controlling the first and second variable current sources based on a difference between an operating point voltage of a differential output of the transconductor and a reference voltage,
• said integrator further comprising:
• a capacitor connected between an output terminal of the first transconductor and an output terminal of the common-mode feedback circuit;
• and
• a capacitor connected between an output terminal of the second transconductor and the output terminal of the common-mode feedback circuit.

An integrator comprising:

• a transconductor for receiving a differential voltage signal and outputting a differential current signal, comprising:
• a first transconductor and a second transconductor for receiving the differential voltage signal and outputting a single-end current signal,
• wherein an inversion input terminal of one of the first and second transconductors is connected with a non-inversion input terminal of the other, and the transconductor outputs a current signal output from each of the first and second transconductors as the differential current signal,
• wherein the first and second transconductors each comprise:
• a first voltage-to-current conversion circuit and a second voltage-to-current conversion circuit for receiving a positive side and a negative side of the differential voltage signal, respectively;
• and
• a current mirror circuit having an input side and an output side to which the first and second voltage-to-current conversion circuits are connected, respectively,
• wherein the single-end current signal is output from a connection point between the second voltage-to-current conversion circuit and the current mirror circuit,
• said transconductor further comprising:
• a first variable current source and a second variable current source connected any one of the input side and the output side of the current mirror circuit in each of the first and second transconductors;
• and
• a common-mode feedback circuit for controlling the first and second variable current sources based on a difference between an operating point voltage of a differential output of the transconductor and a reference voltage,
• said integrator further comprising:
• a capacitor connected between differential output terminals of the transconductor;
• a capacitor connected between an output terminal of the first transconductor and an output terminal of the common-mode feedback circuit;
• a capacitor connected between an output terminal of the second transconductor and the output terminal of the common-mode feedback circuit;
• a capacitor connected between input and output terminals of the current mirror circuit in the first transconductor;
• and
• a capacitor connected between input and output terminals of the current mirror circuit in the second transconductor.