| 摘要 |
PROBLEM TO BE SOLVED: To provide a controller for a voltage conversion circuit, with which the presence of abnormality of a path, to which an output voltage of the voltage converting circuit is applied, is decided more appropriately. SOLUTION: The output voltage of a DC-DC converter is supervised through a monitor wire L3. A PWM comparator 70 generate a pulse controlling the output voltage, based on the output by an error amplifier 66 for the difference between a voltage of a node Na and a voltage of a reference voltage source 68. A differential amplifier 78 outputs a signal, which corresponds to a voltage difference between a voltage of a node Nb and a voltage of a node Nc to a disconnection detecting comparator 80. When the signal, according to the voltage difference, becomes the threshold voltage or more of a reference voltage source 82, the disconnection detecting comparator 80 outputs a signal of logic "H" to a filter circuit 84. When the state of the logic "H" output from the disconnection detecting comparator 80 continues for a specified time or longer, the filter circuit 84 outputs a signal, showing the presence of abnormality which is the signal of the logic "H". COPYRIGHT: (C)2007,JPO&INPIT
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