MODE CONTROL CIRCUIT FOR PLL CIRCUIT AND SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a mode control circuit for a PLL circuit, provided with a high-speed mode and a normal mode that generates a mode switching signal to obtain a stable lock waveform. SOLUTION: The mode control circuit 12 generates a mode-switching signal SW for switching the high-speed mode into the normal mode when the phases of an up-pulse signal PR and a down-pulse signal PP enter within a preset phase difference and to fix to the normal mode.