| 摘要 |
PROBLEM TO BE SOLVED: To provide an overcurrent protection circuit that suppresses heat generation in a semiconductor device for forming a BTL output circuit to an overcurrent generated in an abnormal case such as the case that an output terminal is erroneously short-circuited to the GND or a VCC and that output terminals are short-circuited can prevent breakdown, and can perform protection so that a semiconductor chip itself is not broken even if the BTL output circuit is changed into an integrated circuit. SOLUTION: Both operating current sources of the output circuits 150, 160 are shut off by an overcurrent control circuit 200 to a semiconductor integrated circuit having the output circuits 150, 160 for driving a speaker 101, accompanied by overcurrent detection by both of an overcurrent detection circuit 170 for detecting the overcurrent of the output circuit 150 and an overcurrent detection circuit 180 for detecting the overcurrent of the output circuit 160. The state of the shut-down is held for a prescribed time. After the prescribed lapse of time, the held state is released, thus preventing the overcurrent of the output circuit 150 or 160. COPYRIGHT: (C)2006,JPO&NCIPI
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