| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power supply device less in power loss, improved in response characteristics to the variation of an output and reducible in size, and a power supply driver module suitable for the same. SOLUTION: This driver circuit (110) constitutes the switching power supply device that outputs a voltage obtained by stepping down an input voltage by switch-controlling power transistors (Q1, Q2) by PWM method that make currents flow to a coil (L0). The driver circuit is constituted such that: a signal led out of this side of a final output stage of a high-side gate drive circuit (111) is fed back to a control logic circuit (120) that generates control signals of the gate drive circuits (111, 112) that drive gates of the two power MOS transistors (Q1, Q2) connected in series between two power supply voltage terminals; and a gate drive voltage of the low-side MOS transistor (Q2) is started up in accordance with the variation (rising) of a signal that is obtained by delaying for a prescribed time the signal led out of this side of the final output stage. COPYRIGHT: (C)2006,JPO&NCIPI
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