| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a voltage-controlled oscillator that achieves higher oscillation frequency with consumption current increase being minimized. <P>SOLUTION: The voltage-controlled oscillator comprises: a first voltage-controlled current source (10) which is connected directly or indirectly to first reference potential application means (Vdd or Vss) and generates driving current in response to control voltage (Vcont); a ring oscillator (20) oscillating with a cycle expressed as 2*N*Td in which an odd-numbered N-stage inverter (X1 to XN) with a delay time Td is connected in ring shape so that output of a final stage of the inverter is applied to input of an initial stage of the inverter, one end of a pair of current-carrying terminals of the inverter is connected to the first voltage-controlled current source in parallel with each other, and the other end of a pair of current-carrying terminals is connected directly or indirectly to second reference potential application means (Vss or Vdd) in parallel with each other; and a comparator (30) that outputs an oscillation signal of which a cycle in response to the terminal voltage of one end of the pair of current-carrying terminals is 2*Td. <P>COPYRIGHT: (C)2012,JPO&INPIT |
