| 摘要 |
A charge coupled device (CCD) frequency divider circuit for dividing the frequency of an input signal comprises a CCD having main, drain, and feedback channels. Input signal charge is injected during each cycle of the input signal into a potential well under a storage electrode that retains a predetermined quantity of charge. Overflow from the storage electrode is detected by a sensing electrode that is normally maintained in a transfer state, causing the sensing electrode to switch to a barrier state. This allows the predetermined quantity of charge to advance to an output while the overflow is dumped out by the drain channel. However, when no overflow is present, the sensing electrode causes the input charge to be transferred into the feedback channel which circulates it to the storage electrode to combine with another input charge received by the storage electrode during a subsequent cycle of the input signal. The feedback channel includes delay electrodes which delay the charge in the feedback channel from combining with the input charge until a predetermined number of cycles of the input signal have passed. The frequency of the input signal is divided by an even number dependent upon the number of cycles by which the delay electrodes delay the charge in the feedback channel from combining with a new input charge to give a whole number of output cycles. Initialization of the circuit may also be accomplished by adding to or dumping the charge that is circulating in the feedback channel.
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