| 摘要 |
PURPOSE:To improve the accuracy of output data by correcting the fluctuation in a constant current or a reference voltage, by controlling the constant current value or the reference voltage of a constant current source circuit with an output of a data comparator. CONSTITUTION:A switch S4 is changed over (b), an input is set to 0V, and converted at an A/D converter 20, compared with a reference zero data D0 at an EX OR gate 25, and a signal corresponding to an error is inputted to a control circuit 30 for a reference voltage for comparison of the converter 20 for the correction of the reference voltage. The switch S4 is changed over (c), an input is set to Vmax, the result is converted at the A/D converter 20, compared with a reference data Dmax at an EX OR gate 26, and a signal in response to an error is inputted to a constant current value controlling circuit 31 of a constant current source circuit 7 of the converter 20 for the correction of the constant current value, allowing to improve the accuracy of output data. |
