| 摘要 |
PROBLEM TO BE SOLVED: To easily prevent the erroneous detection of an overcurrent caused by noise. SOLUTION: A current of a motor coil is detected on the basis of a voltage generated by a resistor arranged at the grounding side of an H-bridge; a first source transistor and a second sink transistor are turned on for a prescribed time in order to increase a current of the motor coil; the first source transistor and the second sink transistor are turned on when increasing the current of the motor coil in order to make the current of the motor coil reach a prescribed amount after a lapse of the prescribed time; a first sink transistor and either of the second sink transistor and a second source transistor are turned on when decreasing the current of the motor coil; and the first and second sink transistors are turned off when it is detected that a current flowing to the first sink transistor or the second sink transistor is an overcurrent not smaller than a prescribed current in amount on the basis of the voltage generated by the resistor when decreasing the current of the motor coil. COPYRIGHT: (C)2009,JPO&INPIT
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