| 摘要 |
PROBLEM TO BE SOLVED: To detect an output current highly accurately without efficiency decline caused by a detection resistance. SOLUTION: This current detection circuit 5 has a level shift circuit 50 constituted of a resistance R<SB>1s</SB>and a current source I<SB>1s</SB>; a low-pass filter 51 drawn out from a node M through a signal wire, and constituted of a resistance R<SB>LP1</SB>and a capacitor C<SB>LP1</SB>; a switch SW1 provided on a subsequent stage of the level shift circuit 50; a switch SW2 provided on a subsequent stage of the low-pass filter 51; a low-pass filter 52 provided on a subsequent stage of the switch SW1 and the switch SW2, and constituted of a resistance R<SB>LP2</SB>and a capacitor C<SB>LP2</SB>; an operation amplifier 53; a switch SW3 provided between an output terminal and an inversion input terminal of the operation amplifier 53; and a capacitor C<SB>S</SB>provided between the inversion input terminal of the operation amplifier 53 and the GND. COPYRIGHT: (C)2007,JPO&INPIT
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