| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a phase locked loop capable of reducing phase noise in a locked state. <P>SOLUTION: The phase locked loop 10 is provided with a phase comparator 11, a charge pump circuit 12, a loop filter 13, a voltage controlled oscillator (VCO) 14, and an 1/N frequency divider 15. The phase comparator 11 and the charge pump circuit 12 are constituted so as to satisfy K<SB>p2</SB>>K<SB>p1</SB>in an I<SB>o</SB>-Δϕ characteristic, wherein K<SB>p1</SB>indicates an inclination K<SB>p</SB>in ¾Δϕ¾>Δϕ<SB>0</SB>, K<SB>p2</SB>indicates an inclination K<SB>p</SB>in ¾Δϕ¾≤Δϕ<SB>0</SB>, the inclination K<SB>p</SB>is defined by K<SB>p</SB>=dI<SB>0</SB>/dΔϕ and the Δϕ<SB>0</SB>is a constant indicating a prescribed phase error. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
