Driver and amplifier circuitry

A multiple channel receiver circuit, comprising:

• a first differential amplifier having a first input which receives a first input signal, a second input which receives a second input signal, and an output which provides a first received channel signal;
• a second differential amplifier having a first input which receives a third input signal, a second input which receives a fourth input signal, and an output which provides a second received channel signal;
• and
• a summing differential amplifier having a first input which receives the first input signal, a second input which receives the second input signal, a third input which receives the third input signal, a fourth input which receives the fourth input signal, and an output which provides a third received channel signal, the third received channel signal derived from common mode voltages of the first, second, third, and fourth signals.

An amplifier circuit, comprising:

• a first input which receives a first input signal;
• a second input which receives a second input signal;
• a third input which receives a third input signal;
• a fourth input which receives a fourth input signal;
• a first summing circuit coupled to the first input and the second input and having an output which provides a first sum of the first input signal and the second input signal;
• a second summing circuit coupled to the third input and the fourth input and having an output which provides a second sum of the third input signal and the fourth input signal;
• a first differential output which provides a first difference between the first and second sums;
• and
• a second differential output which provides a complement of the first difference.

A multiple channel driver and receiver circuit, comprising:

• a first current-steering driver circuit having an input which receives a first channel signal, a first output which provides a first output signal, a second output which provides a second output signal, and a first shared portion;
• a second current-steering driver circuit having a first input which receives a second channel signal, a first output which provides a third output signal, a second output which provides a fourth output signal, and a second shared portion;
• a third current-steering driver circuit, coupled to the first and second current-steering driver circuits, having a third input which receives a third channel signal and uses the first and second shared portions to selectively adjust common mode voltages of the first and second current-steering driver circuits;
• a first differential amplifier having a first input which receives the first output signal, a second input which receives the second output signal, and an output which provides a first received channel signal;
• a second differential amplifier having a first input which receives the third output signal, a second input which receives the fourth output signal, and an output which provides a second received channel signal;
• and
• a summing differential amplifier having a first input which receives the first output signal, a second input which receives the second output signal, a third input which receives the third output signal, a fourth input which receives the fourth output signal, and an output which provides a third received channel signal, the third received channel signal derived from a first common mode voltage of the first and second output signals and a second common mode voltage of the third and fourth output signals.

A method for transmitting multiple channel signals, comprising:

• receiving a first channel signal;
• in response to receiving the first channel signal, steering a first current through a first shared switch;
• receiving a second channel signal;
• in response to receiving the second channel signal, steering a second current through a second shared switch;
• receiving a third channel signal;
• and
• in response to receiving the third channel signal, steering a third current through at least one of the first shared switch and the second shared switch.

A multiple channel driver circuit, comprising:

• first receiving means for receiving a first channel signal;
• second receiving means for receiving a second channel signal;
• third receiving means for receiving a third channel signal;
• first steering means for steering a first current through a first shared switch in response to receiving the first channel signal;
• second steering means for steering a second current through a second shared switch in response to receiving the second channel signal;
• and
• third steering means for steering a third current through at least one of the first shared switch and the second shared switch in response to receiving the first channel signal.

A method for receiving multiple differential channel signals, comprising:

• receiving a first input signal and a second input signal, the first input signal and the second input signal corresponding to a first differential signal;
• receiving a third input signal and a fourth input signal, the third input signal and the fourth input signal corresponding to a second differential signal, and the first differential signal and the second differential signal corresponding to a third differential signal;
• providing a first received channel signal corresponding to the first differential signal;
• providing a second received channel signal corresponding to the second differential signal;
• and
• providing a third received channel signal corresponding to the third differential signal.

A multiple channel receiver, comprising:

• first receiving means for receiving a first input signal and a second input signal, the first input signal and the second input signal corresponding to a first differential signal;
• second receiving means for receiving a third input signal and a fourth input signal, the third input signal and the fourth input signal corresponding to a second differential signal, and the first differential signal and the second differential signal corresponding to a third differential signal;
• first providing means for providing a first received channel signal corresponding to the first differential signal;
• second providing means for providing a second received channel signal corresponding to the second differential signal;
• and
• third providing means for providing a third received channel signal corresponding to the third differential signal.