Dual Bandwidth Phase-Locked Loop Circuit

摘要

The present invention relates to a dual-bandwidth phase locked loop circuit, which is difficult to use in a communication system requiring fast switching because it takes more than a few tens of milliseconds to lock a frequency due to a narrow bandwidth in a conventional PLL. There was this.;Therefore, the present invention provides a wide bandwidth effect by reducing the locking time by flowing more current than the normal state in the charge pump operation to the desired voltage level quickly, and also reduces the current to a steady state when the charge pump is near There is an effect that enables precise control of the frequency by zooming.