摘要 |
An LC oscillator includes inductors, a variable capacitor section, an adjusting section for varying the capacitance of the variable capacitor section in response to a control voltage supplied in accordance with a digital control signal, and an additional variable capacitor section for varying its capacitance in response to an additional control voltage. The variable capacitor section includes first to Kth capacitors, where K is an integer greater than one. The adjusting section includes buffer section, each of which selectively generates one of a first voltage and a second voltage lower than the first voltage in response to a kth bit of the digital control signal, where k is an integer varying from one to K, thereby generating first to Kth control voltages to be supplied to the first to Kth capacitors. |