| 摘要 |
A folding stage of the convertor has means for sensitizing, inhibiting and enabling signal paths through the convertor such that in a first operating condition, first and second inputs to the stage are switched through to corresponding inputs of a differential amplifier (3) of the respective stage. In a second operating condition a low auxiliary potential is applied to the first input and a high auxiliary potential is applied to the second input. In a third condition a high auxiliary potential is applied to the first input and a low auxiliary potential is applied to the second input. In a fourth condition both inputs are set to a potential between the high and low potentials. Means (13) are also provided to set the amplifier outputs to the same potential in dependence on signals on a control bus (18). Means are also provided feed a signal from a comparator or differential amplifier via an interrogation bus (19) to a control unit (20). Independent claims also cover a self calibration method. |
