| 摘要 |
PURPOSE:To obtain a phase comparator with simple configuration in which phases are compared at a high speed. CONSTITUTION:A NAND gate of the precharge system comprising transistors(TRs) Q35-Q37 compares phases. Then the comparison result of a NAND gate NA15 is limited and outputted for a period when an input clock CLKref is logical 1 to detect a phase lag of an internal clock CLKint with respect to the input clock CLKref. The phase lead of the internal clock CLKint with respect to the input clock CLKref is compared by replacing the relation of blocks received by phase detection sections PD21, PD22. Thus, the phases are compared at a high speed with a simple circuit comprising the precharge system NAND gate and the NAND gate NA15. |
