| 摘要 |
PROBLEM TO BE SOLVED: To provide a current feeding circuit composed of a current chopper D-class amplifier which is superior in control accuracy and reducible in cost. SOLUTION: An output current Io to be supplied to a load 105 is controlled by a full bridge composed of transistors 110a, 110b, 120a and 120b. The power amplifier circuit is equipped with mirror transistors 220a and 220b provided to comprise a current mirror together with the transistors comprising the full bridge, and detection resistors 230a and 230b serially connected with the mirror transistors 220a and 220b. In accordance with voltages detected in the detection resistors 230a and 230b, an operation of the full bridge is controlled. Further, ON/OFF of transistors belonging to one bridge is controlled in accordance with a voltage drop in the detection resistor provided in accordance with the other bridge. COPYRIGHT: (C)2004,JPO
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