| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly efficient, inexpensive insulated DC-DC converter having a high voltage input and large capacity by avoiding a phase delay problem resulting from a photo coupler and an error amplifier and enabling satisfactory driving of power switch elements. SOLUTION: A power switch element (Q1) is made to turn on by rising the output voltage of the OUT terminal in a PWM control circuit (8). When the output voltage of the insulated DC-DC converter (100) exceeds a reference voltage, an on-period control circuit (16) generates an off-timing signal. The off-timing signal is input into the current detection terminal (CS) in the PWM control circuit (8) through the off-timing signal input circuit (32), causing the PWM control circuit (8) to lower an OUT terminal voltage. Accordingly, the power switch element (Q1) is turned off. COPYRIGHT: (C)2009,JPO&INPIT |
