Patent ID: 11936396
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Measurement (Instruments)
Classification: CPC H  G | IPC H

Claim 5:
6. An AD converter with self-calibration function that does not require an instrument for calibration, the AD converter comprising:
a reference voltage unit that generates a reference voltage;
a summation and conversion unit that has two or more unit voltages serving as units of amount of change in a summed voltage, and during conversion, sums up any one unit voltage of the two or more unit voltages until the summed voltage exceeds a predetermined threshold voltage, with an input voltage being an initial value of the summed voltage; and
a control unit including a calibration control section that calibrates the two or more unit voltages and an offset voltage of a comparator at a time of calibration, and a conversion control section that determines a polarity of the offset voltage of the comparator and thereafter converts the input voltage to a digital value during conversion.