Patent ID: 11955985
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An AD converter, comprising:
an integration unit that uses an input voltage as an initial value and repeats an operation of integrating one or both of two types of unit voltages with the input voltage, thereby generating an integrated voltage;
a switching threshold voltage unit that includes two types of threshold voltages causing the operation of integrating to be terminated;
a comparator that compares the integrated voltage with the threshold voltages;
an integration determination unit that, before the operation of integrating is started, causes the comparator to compare the input voltage with a rough adjustment threshold voltage corresponding to a larger one of the unit voltages;
a unit voltage switching control unit that, when the rough adjustment threshold voltage is larger than the input voltage, controls the integration unit to generate the integrated voltage by using the two types of unit voltages; and
a single unit voltage control unit that, when the rough adjustment threshold voltage is smaller than the input voltage, controls the integration unit to generate the integrated voltage by using only a smaller one of the unit voltages.