Patent ID: 7030679

Claim:
A multiplexer circuit, comprising a plurality of switched differential amplifier circuits each including a pair of differential inputs and a pair of differential outputs, with each pair of differential inputs accepting a corresponding pair of voltage input signals including a first input signal and a second input signal, wherein each switched differential amplifier circuit comprises: a first switched input stage including an input to accept the first input signal and an output, said first switched input stage configured to, when selected, present a substantially unmodified version of the first input signal at its said output, and said first switched input stage configured to, when deselected, produce a first rejection voltage signal of substantially equal magnitude and opposite polarity to the first input signal in order to reject said first input signal and thereby present a substantially constant voltage at its output regardless of variations in the first input signal; and a second switched input stage including an input to accept the second input signal and an output, said second switched input stage configured to, when selected, present a substantially unmodified version of the second input signal at its said output, and said second switched input stage configured to, when deselected, produce a second rejection voltage signal of substantially equal magnitude and opposite polarity to the second input signal in order to reject said second input signal, and thereby present a substantially constant voltage at its said output regardless of variations in the second input signal.