| 摘要 |
PROBLEM TO BE SOLVED: To obtain an integrated circuit which is used for a switching power supply with which a switching frequency can be changed over in an ordinary operating state and a standby state and which can adjust the switching frequency in the ordinary operating state. SOLUTION: In order to adjust the charging current and the discharge current of a capacitor 25 which decides the oscillation frequency of an oscillation circuit, N-channel MOS transistors 35, 36, 37 which are connected in parallel with an N-channel MOS transistor 34 and which were weighted are installed. In addition, diodes 41, 42, 43 which are connected in series with the MOS transistors are installed. Electrode pads 47, 48, 49 are installed at cathodes of the diodes. A breakdown current is made to flow into the diodes selectively, they are short-circuited, and the MOS transistors which were weighted are selected. Thereby, the charging current and the discharge current can be made variable.
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