| 摘要 |
PROBLEM TO BE SOLVED: To provide an integrated circuit for oscillation designed to shorten an oscillation startup time and reduce current consumption during a steady oscillation state.SOLUTION: The integrated circuit for oscillation comprises: an oscillation unit 1 having a CMOS inverter configured by connecting MOS transistors PM1, NM1 in series, a feedback resistor 11 connected in parallel to the CMOS inverter, and load capacitances 12, 13 connected to each of the input terminal and output terminal of the CMOS inverter, and used by connecting a crystal vibrator 2 thereto; an oscillation detection circuit 3 for detecting a change in the amplitude of an oscillation signal outputted from the oscillation unit 1; and a bias circuit 4 for adjusting a supply current to the CMOS inverter by a detection signal of the oscillation detection circuit 3. When, after oscillation startup, the amplitude of the oscillation signal is not detected by the oscillation detection circuit 3 to have reached a size greater than or equal to a prescribed size, a current satisfying oscillation condition is supplied to the MOS transistor PM1; when the amplitude of the oscillation signal is detected to have reached a size greater than or equal to a prescribed size, a current smaller than the above is supplied. |
