| 摘要 |
PROBLEM TO BE SOLVED: To provide an insulated DC-DC converter for improved control precision of an output voltage. SOLUTION: When a switching element 4 is turned off, a main winding 11a of a choke coil 11 is applied with a voltage Vout of a load 6, or both-end voltage of a capacitor 13, since a diode 7 is turned off and a diode 8 is turned on. Here, a voltage which is proportional to a turn ratio occurs at an auxiliary winding 11b of the choke coil, and a hold circuit 31 sample-holds at the timing of gate-off of the switching element 4 through an amplifier 30. Just after gate-off of the switching element 4, sample-holding is performed at the timing which is delayed by a delay circuit 32 because both end voltage of the choke coil 11 transitionally fluctuates from negative voltage to positive voltage. The pulse width of the switching element is controlled based on the voltage that has been sample-held. COPYRIGHT: (C)2010,JPO&INPIT |
