| 摘要 |
PROBLEM TO BE SOLVED: To realize stabilized operation while ensuring a maximum duty even in a DC/DC converter having a high switching frequency. SOLUTION: The comparator comprises a differential circuit 12 provided with a diode connection load where the drain and the gate are connected, a self-bias differential amplifier 13 receiving the output from the differential circuit 12, and an output stage 14 wherein a circuit power supply is shared among the differential circuit 12, the self-bias differential amplifier 13 and the output stage 14 through an internal power supply circuit 11. In a DC/DC converter comprising a first comparator for comparing the output voltage from an error amplifier with a saw-tooth voltage, a second comparator for comparing a voltage level determining a soft start time with the saw-tooth voltage, and a circuit performing switching control of a switching transistor with the outputs from both comparators, the first and second comparators employ above-mentioned arrangement. COPYRIGHT: (C)2005,JPO&NCIPI
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