| 摘要 |
PROBLEM TO BE SOLVED: To improve a yield by correcting the deviation of frequency characteristics in an LC oscillation circuit. SOLUTION: This LC oscillation circuit is provided with inductors 1 and 2, variable capacitor parts 12a and 12b whose capacities are changed according to the a control voltage applied on the basis of a digital control signal, and additional variable capacitor parts 13a and 13b whose capacities are changed according to an additional control voltage. The variable capacitor parts are respectively provided with first to Kth (K is an integer which is 2 or greater capacitors and a buffer part for generating first to Kth control voltages as the control voltage in accordance with the digital control signal and for applying them to the first to Kth variable capacitors. In accordance with the kth (k is one of integers from 1 to K) bit logic of the digital control signal, the buffer part selectively generates a first voltage and a second voltage lower than the first voltage as the kth control voltage. COPYRIGHT: (C)2004,JPO
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