| 摘要 |
In general, in one aspect, an apparatus includes a phase frequency detector, a charge pump, a voltage controlled oscillator, an integral capacitor to maintain an integral charge and provide an integral voltage, and a mutual-charge canceling sample reset (MCSR) capacitor to maintain a proportional charge and provide a proportional voltage each reference clock cycle. The MCSR includes a first proportional capacitor, a second proportional capacitor in parallel to, and having substantially identical capacitance value as, the first proportional capacitor, a first set of switches to provide direct coupling of the first and second proportional capacitors, and a second set of switches to provide cross coupling of the first and second proportional capacitors. The first and second set of switches alternatively turn on and off every reference clock cycle so that set of switches coupling the first and second proportional capacitors alternates every reference clock cycle.
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