| 摘要 |
PURPOSE:To improve linearity precision while correcting an error due to the output-value variation of a reference power source, by measuring and calculating the input and output relation of a DA converter and by setting a corrected value for the DA converter on the basis of the input and output relation. CONSTITUTION:A control circuit 6 sets a correcting operation state, and pattern data consisting of 2<4> bits obtained by changing the order of the high-order four bits of input digital data 7 is generated and inputted to a DA converter 1; and the obtained output analog value E0 is converted by a high-precision AD converter 3 into a digital value 10, and the input and output relation of the DA converter 1 is calculated by an arithmetic circuit 4 on the basis of the bit data 9 of the input digital data 7 to further calculate the difference. Then, 2<4> corrected values are stored in a storage circuit 5. When the control circuit 6 inputs the digital data 7 to the DA converter 1 for DA converting operation, the corrected values are read out of the storange circuit 5 and the correction of the correcting DA converter 1 is performed. |
