| 摘要 |
<P>PROBLEM TO BE SOLVED: To shorten a lock-in time by controlling a PLL circuit according to variations of a process, temperature, a source voltage, etc. <P>SOLUTION: The PLL circuit has a phase detector 1, a charge pump 2, a loop filter 3, and a voltage-controlled oscillator 4 which are connected in a loop, and includes a charge pump 7 for acceleration which can operate in parallel to the charge pump 2, and a control means 5 of controlling the operation timing of the charge pump 7 for acceleration. <P>COPYRIGHT: (C)2009,JPO&INPIT |
