| 摘要 |
PROBLEM TO BE SOLVED: To provide a current-detecting circuit for detecting reverse current flowing in a switch element of a switching power supply, and to provide the switching power supply for improving the transient response characteristics by using the current-detecting circuit. SOLUTION: The current-detecting circuit has an offset-voltage source comprising the switching element 1, an auxiliary switching element 2, an offset resistor 7 and a current-source circuit 8, and a compensation circuit comprising a differential amplifier 4 and a compensating transistor 6 for adjusting an output current from the auxiliary switching element 2 so as to make the potential outputted from the switching element 1 via the offset resistor 7 equal to the output potential from the auxiliary switching element 2. The detection level of the current flowing in the switching element 1 is shifted by an offset amount. COPYRIGHT: (C)2006,JPO&NCIPI
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