| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power supply device which generates a plurality of output voltages from one input voltage while optimizing the control of synchronization between an output switch element and a synchronous rectification element, and the control of output switching. SOLUTION: This switching power supply device 100 generates output voltages Vout1 to VoutN of an N system from one input voltage Vin by outputting in a distributed manner the accumulated energy of a coil 30 while sequentially switching N synchronous rectification elements 21 to 2N sharing the coil 30 and the output switch element 10. A switching control means of the switching power supply device is composed of: a duty selection circuit 91 which generates a reference duty signal D by selecting duty signals D1 to DN for output return control at each prescribed period, and a control signal generation circuit 92 which generates a first control signal G1 and second control signals G21 to G2N on the basis of the reference duty signal D. COPYRIGHT: (C)2010,JPO&INPIT
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