| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power supply controller for controlling power supply through on-off operation of a semiconductor element based on a pulse train-like control signal while performing protective operation for preventing breakdown of a semiconductor switch element and capable of preventing superfluous protection appropriately. <P>SOLUTION: The power supply controller 10 comprises a thermal FET 11 provided with an FET 20 performing on/off operation based on a PWM control signal. The thermal FET 11 is provided with an overheat protection circuit 42 and a signal corresponding to the voltage level at the gate terminal G is inputted to a microcomputer 12 by an input level detection means 50 provided on the outside of the thermal FET 11. The microcomputer 12 performs stop operation of a PWM control signal when the voltage level at the gate terminal G reaches the interruption level of the FET 20 by a predetermined number of times. On the other hand, the microcomputer 12 sustains output without performing stop operation of a PWM control signal when the voltage level of a power supply 30 for vehicle is below a reference level. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
