| 摘要 |
PROBLEM TO BE SOLVED: To prevent an overshoot from occurring in an output when initiating a built-in gain control circuit, without increasing power consumption. SOLUTION: After an internal control voltage 200 which controls a gain of a gain control circuit 10 reaches a setting value, a bias voltage 202 which operates the gain control circuit 10, reaches a setting value, and a time until returning the bias voltage 202 which becomes the setting value, to an initial value is set shorter relatively to a time for allowing the bias voltage 202 reaching the setting value from its initial value. Therefore, the gain control circuit 10 can be turned into an active state by the bias voltage 202 after its gain is set by the internal control voltage 200, thereby eliminating the occurrence of the overshoot caused by a change of the gain from an output 400 of the gain control circuit 10. Further, the gain control circuit 10 is turned on and off as needed, so that power consumption does not increase. COPYRIGHT: (C)2005,JPO&NCIPI
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