| 摘要 |
PROBLEM TO BE SOLVED: To provide a pulse control apparatus capable of performing PFM control without dropping a switching frequency. SOLUTION: In a PFM control section 27, a series of control processes of performing A/D conversion on a feedback signal of a feedback transformer 21, sampling the converted signal and performing PFM operation based on the sampling information are repeatedly performed in a predetermined control period, so that a PFM pulse frequency is sequentially determined and set to a pulse driving signal generating section 26. Furthermore, after the end of PFM operation, processing is shifted to the next control period from a point of time when one PFM pulse fed back from the pulse driving signal generating section 26 is completely input. Thus, even if the switching frequency increases, the control period is determined just for the time irreducibly required for PFM operation. COPYRIGHT: (C)2007,JPO&INPIT
|
