| 摘要 |
PROBLEM TO BE SOLVED: To suppress phase noise by varying the gm of a MOS transistor used in a voltage controlled oscillator. SOLUTION: Drains of a plurality of MOS transistors TR12, TR13 or the like are connected to a drain of a MOS transistor TR11 via a plurality of switches SW1, SW2 or the like. The MOS transistors TR12, TR13 or the like are selectively connected in parallel with the MOS transistor TR11 by turning on or off the switches SW1, SW2 or the like by using gm setting digital data obtained from frequency setting digital data to set an oscillated frequency. Thus, a current supplied to a resonance circuit 10 is varied. COPYRIGHT: (C)2007,JPO&INPIT
|
