| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit apparatus including a VCO to form a low jitter reference frequency signal at a high-frequency by a simple configuration. <P>SOLUTION: The apparatus is provided with a first current mirror circuit composed of a second conductive MOSFET to receive the drain current of the first MOSFET of a first conductive type to receive a control voltage, a second current mirror circuit composed of the first conductive MOSFET to receive the output current of the first current mirror circuit, and a ring oscillator composed of a plurality of amplification circuits to control an operation current based on the output current of the second current mirror circuit. The second current mirror circuit switches an input-output current ratio by a control signal, and the ring oscillator sets a maximum input-output current ratio in a range to meet an allowable value. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
