| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an oscillator whose sampling frequency of a ΔΣ circuit section in a fractional N type PLL circuit can be varied and whose quantization noise can be varied. <P>SOLUTION: The oscillator comprises: a reference signal input terminal 200, a PD 100 connected to the input terminal, and a CP 101 which accepts as its input the output of a phase comparator; an LPF circuit 102 connected to the CP 101; a VCO circuit 103 to which the output is input and a frequency divider 104 which divides the frequency of the output of the VCO circuit 103 before being output to the PD 100; a LPF circuit 105 connected to the frequency divider 104 and a ΔΣ circuit 106 connected to the LPF circuit 105; and a clock circuit 107, connected to the ΔΣ circuit 106, which includes a plurality of oscillator sections 110, 111 and 112 and a control circuit 108 to switch between the oscillator sections. The oscillator is composed with a monolithic oscillator, which is comprised of a vibrator and an electronic circuit. <P>COPYRIGHT: (C)2013,JPO&INPIT |
