| 摘要 |
PROBLEM TO BE SOLVED: To provide an offset canceller capable of outputting a signal during an operation for offset compensation and compensating an offset caused by a capacitive element and a resistive element externally connected to an operational amplifier. SOLUTION: A drive circuit 10 includes a plurality of output circuits (#1 to #n+1) 16, which respectively provide outputs of drive signals from one-side outputs 14 to a plurality of output terminals (#1 to #n) 12 and provide outputs of the drive signals from the other-side outputs 18. The outputs 14 and the outputs 18 are connected to a plurality of output selection circuits (#1 to #n) 20, which select either of signals outputted from the two output circuits 14 adjacent to each other and provide outputs of the selected signals to the output terminals 12. The other outputs 18 of the output circuits (#1 to #n+1) 16 are connected to a discrimination circuit 30, which compares the signal 18 with a reference voltage, outputs a discrimination signal to an output 40 in response to a result of the comparison in a prescribed timing, and the output circuits 16 carry out offset canceling in response to the output 40. COPYRIGHT: (C)2007,JPO&INPIT
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