| 摘要 |
A phase-controlled current source for phase-locked loop, the phase-locked loop comprises of a voltage-controlled oscillator to associate a charging path or discharging path in order to generate an output signal and the output signal is further sensed so as to generate a loop signal, then, together with a reference signal, these signals are used to control phase-controlled current source. Phase-controlled current source comprises of a status memory and a controllable current source and the status memory receives reference signal and loop signal in order to generate an energy-triggering/energy-removing signal, controllable current source then follows the energy-triggering/energy-removing signal to decide if to perform charging or discharging behavior; after charging or discharging behavior is decided, loop signal will decide the charging path or discharging path for the controllable current source based on reference signal so as to perform charging or discharging behavior. Phase-controlled current source is used in the current invention which can eliminate the inherent dead zone problem in the prior art phase detector and electric charge pump. Additionally, the electrical circuit is simple and no signal feedback mechanism needs to be adopted, therefore, the system operation frequency can be greatly enhanced.
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