| 摘要 |
PROBLEM TO BE SOLVED: To provide a DC output offset detection circuit for a BTL connection amplifier with a simple circuit configuration, with which the problem that the inverse base-emitter voltage of a transistor used for detecting a DC output offset gets higher can be solved. SOLUTION: Resistors 4, 5 connected in series are connected between an output terminal 1 and ground of the BTL connection amplifier D, resistors 6, 7 connected in series are connected between an output terminal 2 and ground, and a capacitor 8 interconnects the connecting point A of the resistors 4, 5 and the connecting point B of the resistors 6, 7. The emitter of a transistor 9 is connected to the connecting point A, the base of the transistor 9 is connected to the connecting point B, the emitter of a transistor 10 is connected to the connecting point B, and the base of the transistor 10 is connected to the connecting point A. Collectors of both the transistors 9, 10 are connected in common, the connecting point C of the collectors is connected to ground via a resistor 11, and a voltage drop through the resistor 11 is used for a DC offset detection output. COPYRIGHT: (C)2004,JPO&NCIPI
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