| 摘要 |
<p>A circuit arrangement and process is provided for converting an analogue signal into a digital signal or converting a digital signal into an analogue signal. The circuit arrangement has first and second capacitances with a charge transfer device between the capacitances for providing a stepped exchange of charge therebetween. For analogue to digital conversion, a device is provided which brings the second capacitance to a given charge state for each step exchange. An evaluation device evaluates the charge state of the second capacitance for each stepped exchange until the charge on the second capacitance is below a given level. A counting device counts each of the stepped exchanges of charge such that the total count provides the corresponding digital signal. For digital to analogue conversion, in one embodiment a charge is placed on the second capacitance. The charge transfer device then removes equal quantities of charge in a plurality of steps and transfers this charge to the first capacitance. The number of steps corresponds to the number of the digital signal. Finally, a read-out circuit detects the total charge transferred to the first capacitor and provides a corresponding analogue signal. The charge transfer device used for either analogue to digital or digital to analogue conversion preferably comprises a charge coupled device having electrodes over an insulating layer formed on a substrate.</p> |
