Patent ID: 6909391

Claim:
An analog to digital signal conversion system comprising: an analog to digital converter having a digital signal input line; a fully differential reference voltage supply coupled to said analog to digital converter by means of a differential signal path, said fully differential reference voltage supply comprising: a reference resistor adapted to exhibit a reference voltage between first and second nodes thereof in response to a reference current impressed thereupon; a fully differential amplifier circuit having third and fourth differential signal input nodes, a common mode voltage input node, and fifth and sixth differential signal output nodes, said third and fourth differential signal input nodes coupled to said first and second nodes respectively through respective first and second capacitors, said fifth and sixth differential signal output nodes coupled to said third and fourth differential signal input nodes respectively through respective third and fourth capacitors; a source of common mode voltage adapted to be switchingly coupled to both said third and fourth differential signal input nodes; first and second switching devices adapted to switchingly shunt said third and fourth capacitors respectively; and a third switching device adapted to switchingly couple said first and second nodes.