| 摘要 |
PROBLEM TO BE SOLVED: To provide an overvoltage protective circuit capable of avoiding the occurrence of an oscillation state when a DC-DC converter transiently responses, especially when an overvoltage is generated in an output voltage, and stabilizing an output of the DC-DC converter at a predetermined voltage. SOLUTION: When an output voltage Vout reaches an overshoot limit value, an overshoot detection comparator 12 turns off a switch S2. Therefore, a PWM comparator 11 continuously outputs a HIGH signal to turns off a transistor T1, and to turns on a transistor T2. When the output voltage Vout decreases, a clamp voltage from the a clamp circuit is connected to the output voltage Vout. Therefore, the output voltage Vout becomes a clamp voltage, and the output voltage Vout increases gradually, thus suppressing oscillation. COPYRIGHT: (C)2007,JPO&INPIT
|
