Abstract: A dual core crosspoint system includes a differential signal core for receiving N differential input channels with common mode voltage removed and providing m differential output channels with m output stages associated with the m output channels; and a common mode core for receiving N common mode voltage input channels derived from the N differential input channels and providing m common mode voltage output channels simultaneously with the m differential output channels.

Abstract: A transconductance cell includes a positive rail for providing a positive power supply voltage and a negative rail for providing a negative power supply voltage. A pair of voltage inputs, one inverting and one non-inverting, develop a differential voltage input signal having a common mode voltage range from one of the rail voltages to within a volt or less of the other rail voltage. And a pair of cross-coupled transconductor circuits each have: (i.) a source voltage follower responsive to one of the voltage inputs for sourcing relatively unbounded output current at unity voltage gain, (ii.) a sink voltage follower responsive to the other voltage input for sinking unbounded output current to a current output terminal, and (iii) a transconductance resistor connected between the source voltage follower and the sink voltage follower for developing a differential output current proportional to the differential voltage input signal.

Abstract: An amplifier structure includes shield conductors that are provided spatially adjacent to elongated feedback signal lines that couple a feedback circuit to an amplifier input. The shield conductors are provided between the feedback signal lines and a ground plane, which interrupts a parasitic capacitance that otherwise would be established between the feedback signal line and ground. The shield conductors are electrically coupled to the amplifier's outputs which create a capacitance between the output terminal and the feedback signal line. In some embodiments, the capacitance generated between the output terminal and the feedback signal line can suffice as a capacitor in a feedback path of the amplifier and be contained in an integrated circuit die on which the amplifier is manufactured. Optionally, a structure may be provided that eliminates common mode signals on the feedback lines while simultaneously preserving the common mode signals on the amplifier output terminals.

Abstract: A transconductance cell includes a positive rail for providing a positive power supply voltage and a negative rail for providing a negative power supply voltage. A pair of voltage inputs, one inverting and one non-inverting, develop a differential voltage input signal having a common mode voltage range from one of the rail voltages to within a volt or less of the other rail voltage. And a pair of cross-coupled transconductor circuits each have: (i.) a source voltage follower responsive to one of the voltage inputs for sourcing relatively unbounded output current at unity voltage gain, (ii.) a sink voltage follower responsive to the other voltage input for sinking unbounded output current to a current output terminal, and (iii) a transconductance resistor connected between the source voltage follower and the sink voltage follower for developing a differential output current proportional to the differential voltage input signal.

Abstract: An amplifier structure includes shield conductors that are provided spatially adjacent to elongated feedback signal lines that couple a feedback circuit to an amplifier input. The shield conductors are provided between the feedback signal lines and a ground plane, which interrupts a parasitic capacitance that otherwise would be established between the feedback signal line and ground. The shield conductors are electrically coupled to the amplifier's outputs which create a capacitance between the output terminal and the feedback signal line. In some embodiments, the capacitance generated between the output terminal and the feedback signal line can suffice as a capacitor in a feedback path of the amplifier and be contained in an integrated circuit die on which the amplifier is manufactured. Optionally, a structure may be provided that eliminates common mode signals on the feedback lines while simultaneously preserving the common mode signals on the amplifier output terminals.

Abstract: A dual core crosspoint system includes a differential signal core for receiving N differential input channels with common mode voltage removed and providing m differential output channels with m output stages associated with the m output channels; and a common mode core for receiving N common mode voltage input channels derived from the N differential input channels and providing m common mode voltage output channels simultaneously with the m differential output channels.

Abstract: A multi-fferential amplifier system includes an amplifier having a plurality of amplifier inputs and a plurality of amplifier outputs; a plurality of input terminals for receiving a plurality of inputs and being interconnected with the amplifier inputs through a plurality of input impedances, respectively, and a feedback network including a plurality of summing circuits for combining the plurality of amplifier outputs in a plurality of different sets of groups each group numbering one fewer than the plurality, respectively, and feeding back the sum of each group of amplifier outputs to the remaining amplifier input for maintaining the difference between any group of amplifier outputs proportional to the difference of a corresponding group of inputs at the terminals and maintaining the average value of the amplifier outputs constant and unrelated to the inputs at the terminal.

Abstract: A multi-fferential amplifier system includes an amplifier having a plurality of amplifier inputs and a plurality of amplifier outputs; a plurality of input terminals for receiving a plurality of inputs and being interconnected with the amplifier inputs through a plurality of input impedances, respectively, and a feedback network including a plurality of summing circuits for combining the plurality of amplifier outputs in a plurality of different sets of groups each group numbering one fewer than the plurality, respectively, and feeding back the sum of each group of amplifier outputs to the remaining amplifier input for maintaining the difference between any group of amplifier outputs proportional to the difference of a corresponding group of inputs at the terminals and maintaining the average value of the amplifier outputs constant and unrelated to the inputs at the terminal.

Abstract: An output distortion correction amplifier system includes an input stage; a current mirror connected to the input stage; an output stage having its input connected to the input stage and a current mirror and its output connected to the input stage; a compensation impedance connected to the input of the output stage; and a distortion correction circuit for directly sensing the distortion voltage across the output stage and providing to the current mirror a current representative of the distortion voltage for delivering to the compensation impedance a correction current to develop a correction voltage at the input of the output stage to nullify the effect of the distortion voltage.

Abstract: An output distortion correction amplifier system includes an input stage; a current mirror connected to the input stage; an output stage having its input connected to the input stage and a current mirror and its output connected to the input stage; a compensation impedance connected to the input of the output stage; and a distortion correction circuit for directly sensing the distortion voltage across the output stage and providing to the current mirror a current representative of the distortion voltage for delivering to the compensation impedance a correction current to develop a correction voltage at the input of the output stage to nullify the effect of the distortion voltage.

Abstract: An input distortion correction current-feedback amplifier system includes a current mirror; an input stage connected to the input of the current mirror; an output stage connected to the output of the current mirror; a feedback circuit connected from the output stage to the input stage; a compensation impedance connected to the output of the current mirror; and a distortion correction circuit for sensing the distortion voltage across the input stage and providing to the current mirror a current representative of the distortion voltage for delivering to the compensation impedance a correction current to develop a correction voltage at the input of the output stage to nullify the effect of the distortion voltage.