| 摘要 |
PROBLEM TO BE SOLVED: To maintain consumption current of an oscillation circuit at an appropriate level by controlling a variable limiter resistor by the output voltage of a voltage divider circuit dividing a power supply voltage. SOLUTION: A gate voltage generation circuit 4 is composed of the voltage divider circuit consisting of resistors R1 and R2, divides the power supply voltage Vcc and supplies the divided voltage VG to a variable limiter resistor 5. The resistor 5 can use a controllable element by the divided voltage and uses, e.g. the resistance of a p-type MOSFET. The gate voltage VG of the p-type MOSFET constituting the resistor 5 changes in accordance with the power supply voltage Vcc of an LSI, the resistance value of the resistor 5 is increased when the power supply voltage is high, and the resistance value of the resistor 5 is reduced when the power supply voltage is low. As a result, the gain of this oscillation circuit is suppressed to an appropriate level by depending on Vcc, i.e., the power supply voltage of this oscillation circuit without needing control from the outside, and the consumption current of the oscillation circuit can be maintained at an appropriate level.
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