| 摘要 |
PROBLEM TO BE SOLVED: To previously prevent the generating of arm short circuit by discriminating the driving of field effect transistor(FET) by the output of an output monitor circuit, etc., so as to stop the driving of FET by an output buffer. SOLUTION: Output monitoring circuits 22 to 25 for identifying the operating state of first to fourth output buffers 10 to 13 are provided. The output monitor circuit 22 discriminates first power MOSFET to be driven when the output voltage of the first output buffer 10 exceeds a prescribed value, 1.4 V. Similarly, the output monitoring circuits 23 to 25 detect second to fourth power MOSFET to be driven by the second to fourth buffers 11 to 13. Then a logic circuit 21 includes a logic circuit for preventing this arm short circuit. By directly monitoring the output of the output buffers by the output monitoring circuits in this manner, the generation of arm short circuit is momentarily prevented. |
