| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a dc-dc converter capable of improving the efficiency under a low load state. <P>SOLUTION: A dc-dc controller 10 in a dc-dc converter 1 includes a PFM comparator 11 and a PWM comparator 12. When a load current becomes small under a low load state, the PFM comparator 11 operates a switching element at a frequency of 20 Hz or less and, when a load increases and a switching element reaches such a state as to operate at a frequency of 20 Hz or more, the PWM comparator 12 mainly operates the switching element at the frequency of 20 Hz or more. <P>COPYRIGHT: (C)2013,JPO&INPIT |
