Patent ID: 11894858
Assignee: YAMAHA CORPORATION
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An analog to digital (A/D) conversion device comprising:
an amplifier configured to amplify an input analog signal with an analog gain corresponding to a gain state and output the amplified analog signal;
a converter configured to convert the output amplified analog signal to a digital signal and output the digital signal;
a down circuit configured to;
detect the output amplified analog signal exceeding a range defined by a first level: and
upon detecting that the output amplified analog signal exceeds the range defined by the first level, lower bring the gain state to a next lower state corresponding to a one-step lower gain than a current gain of the amplifier; and an up circuit configured to;
detect the output digital signal having been continuously within a range defined by a second level for a predetermined period; and
upon detecting that the output digital signal has been continuously within the range defined by the second level for the predetermined period, increase the gain state to a next higher state corresponding to a one-step higher gain than the current gain of the amplifier,
wherein an absolute value of the second level is smaller than an absolute value of the first level.