| 摘要 |
PROBLEM TO BE SOLVED: To cancel the offset of an electronic apparatus at a low cost with high accuracy. SOLUTION: A comparator 600 compares an output signal from a common mode feedback circuit 702 and connected to a noninverting terminal of the comparator 600 with a differential output (negative) A- from a D/A converter 500 and an analog filter 700 and connected to an inverting terminal of the comparator 600 to apply offset canceling to the output A-. Further, the comparator 600 compares the output signal from the common mode feedback circuit 702 and connected to the noninverting terminal of the comparator 600 with a differential output (positive) A+ from the D/A converter 500 and the analog filter 700 and connected to the inverting terminal of the comparator 600 to apply offset canceling to the output A+. After a series of the operations above, an adder 403 sums output values of latches 404, 405 and a 1/2 circuit 406 halves the result of sum and thereafter the halved result is given to an adder 300 to carry out offset compensation. COPYRIGHT: (C)2005,JPO&NCIPI
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