| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress a delay of switching operation when switching outputs in a power supply device with two power supply circuits different in output voltage. <P>SOLUTION: A transistor switch 308 is connected to a gate of a switching FET 304 connected to the primary side of a transformer of a negative voltage generation circuit 303. The transistor switch 308 is turned on by a positive output PWM signal for controlling a positive voltage generation circuit 310. Even if there is a delay in the operation of a D-A conversion circuit 301, the switching FET 304 is forcibly turned off by the transistor switch 308, the delay of the off-operation of the negative voltage generation circuit 303 is suppressed, and a delay in rising at the generation of a positive voltage from the positive voltage generation circuit 310 is improved. <P>COPYRIGHT: (C)2010,JPO&INPIT |
