| 摘要 |
PURPOSE:To obtain a converter where the conversion error due to the error of the input voltage to comparators is small and the conversion speed can be high and the connection error is small, by using comparator groups, the differential amplifier, analogue switch groups, and so on. CONSTITUTION:Input analogue voltage 11 is compared with the first different reference voltages A (taken out from respective connection points of voltage dividing resistances 14-1-14-4) by comparator groups 13-1-13-3. On a basis of this comparison result, one voltage A is selected by analogue switch groups 17-1-17-4. The differential voltage between this voltage A and voltage 11 is amplified by 18. This output is compared with the second different reference voltages (taken out from respective connection points of voltage dividing resistances 28-1-28-6) at an interval approximately equal to the interval (divided voltage) of voltage A by comparator groups 20-1-20-5. Meanwhile, deviation of the overall gain of one of switch groups 17-1-17-4 and differencial amplifier 18 to the prescribed value is detected by detecting means C (consisting of differential amplifier 31 and comparator 32), and voltage B is controlled by this output. Then, comparison results of comparator groups 13-1-13-4 and 20-1-20-5 are converted to digital codes by 25. |
