| 摘要 |
PROBLEM TO BE SOLVED: To provide an offset correction circuit little affecting a feedback control loop and preventing an error based on offset from remaining in an output current or an output voltage. SOLUTION: An input terminal of an offset holding circuit 7 is connected to a circuit contact where a signal to be fed back from the output side of an error amplifier OP1 to an inverting input terminal of the error amplifier OP1 is generated. The output side of a signal synthesis circuit 6 is connected to a non-inverting input terminal of the error amplifier OP1. Then, the output side of the offset holding circuit 7 and the output side of a first switch circuit 5 are connected to the input side of the signal synthesis circuit 6. An offset signal accumulated in a capacitor C10 in an offset detection period is synthesized with a control signal in the signal synthesis circuit 6 and the synthesized signal acts so as to cancel the offset of all circuit portions of a driver circuit 2 and the offset correction circuit 4. COPYRIGHT: (C)2008,JPO&INPIT
|
