| 摘要 |
PROBLEM TO BE SOLVED: To provide a crystal oscillator integrated circuit which can be made small-sized, by reducing the number of external lead-out terminals. SOLUTION: A crystal oscillator integrated circuit includes a temperature compensation circuit 20, a nonvolatile memory 40 and a crystal oscillator circuit 40; adjusts the capacitance of a variable capacitance element of the crystal oscillator circuit 40 according to the capacitance adjustment data and temperature compensation circuit adjustment data stored in the nonvolatile memory 30; applies to the variable capacitance element a temperature compensation voltage output from the temperature compensation circuit 20; and stabilizes the oscillation frequency, by performing temperature compensation on a crystal vibrator XTAL externally attached to the crystal oscillator circuit 40, wherein a first terminal for inputting/outputting a signal from the outside to/from the temperature compensation circuit 20 is shared with a second terminal for supplying data or a clock for writing data into the nonvolatile memory 30. COPYRIGHT: (C)2008,JPO&INPIT
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