Non-integer frequency divider having controllable error
AssigneeRCA Corporation
InventorEdwin Allen Goldberg
Life of this patent
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Abstract
System and method for dividing an input frequency to produce an output frequency related to the input frequency by a non-integral ratio. The divider ratio is alternated between the integer values bracketing the non-integer ratio according to the accumulated value of known errors associated with each integer divisor value by comparing the accumulated error value to a given value.
Claims4
A circuit, producing from a signal at a first frequency a signal at a second frequency, said first and second frequencies being related by a non-integral ratio, comprising the combination of:
- gating means receptive of said first frequency signal for producing pulses in response thereto when enabled by an enabling signal;
- divider means responsive to said pulses for producing said second frequency signal;
- and
- control means responsive to said second frequency signal for enabling said gating means said control means comprising:
- means for accumulating a known error value associated with said second frequency signal;
- and
- means responsive to said means for accumulating for producing said enabling signal and supplying it to said gating means while the accumulated error value is less than a predetermined value.
The method of dividing a first frequency signal by a non-integer divisor to produce a second frequency signal comprising the steps of:
- producing a train of pulses by gating said first frequency signal;
- dividing said pulse train by an integer value;
- and
- inhibiting the production of said pulse train when said second frequency signal includes an error exceeding a desired value wherein said inhibiting step comprises
- accumulating a known error for each period of said second frequency;
- comparing said accumulated error to a predetermined value;
- and
- producing an inhibiting signal when said comparing step indicates the accumulated error exceeds the predetermined value.
Dependencies are inferred from the claim text.