| 摘要 |
PROBLEM TO BE SOLVED: To provide a correction circuit which has its highly accurate characteristic, despite the variance of the circuit element value by preparing a logic circuit which produces a prescribed control signal to count the oscillation frequency of an oscillation circuit and to fix the oscillation frequency and then varying the value of elements of the oscillation circuit and a correction object circuit based on the control signal. SOLUTION: A correction circuit 100 which controls a correction object circuit 26 has an oscillation circuit 21 whose oscillation frequency is decided by the product of element values of a resistance R and a capacitor C, and a logic circuit 22 which counts the oscillation frequency and produces a control signal CNTL, that depends on the oscillation frequency. The resistance and capacitance values of both circuits 21 and 26 are varied with the signal CNTL. The circuit 2 counts the oscillation frequency for a single period of a clock signal and outputs this count value to a control circuit 25. Then a control code corresponding to the count value is outputted to the circuits 21 and 26 respectively, and their element value are varied. |
