| 摘要 |
A high speed frequency generator is disclosed. The frequency generator includes a frequency oscillator producing an output signal of a predetermined frequency, a first frequency divider frequency-dividing the first frequency oscillator's output signal, and a second frequency divider frequency-dividing an input signal by a predetermined factor. A flip-flop receives a signal generated from the second frequency divider and produces an output signal in accordance with an input clock signal. A pulse-width detector detects a width of the output signal of the flip-flop. A comparing part compares an output signal of the pulse-width detector with a reference value to control a counter that counts to a prescribed digital value that corresponds to a desired frequency. A digital-analog converter converts an output digital value from the counter into an analog value. A voltage controlled oscillator produces a clock signal in response to an output signal of the digital-analog converter and feeds the clock signal back to the second frequency divider.
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