Patent ID: 8687326
Filing Date: 2014-04-01
Classification: H02H,H02M

Abstract:
1. A short circuit protecting device adapted to a direct current to direct current (DC-DC) converter with a soft-start function, wherein a voltage output terminal of the DC-DC converter is capable of increasing an output current in segments in multiple time periods after the DC-DC converter is started, the short circuit protecting device comprising: a voltage sensor connected to the voltage output terminal to sense an output voltage; a start timer generating an enable signal after a predetermined period; and a comparison circuit connected to the voltage sensor and the start timer, wherein the comparison circuit is capable of comparing the output voltage with a predetermined voltage according to the enable signal, wherein the comparison circuit comprises: wherein a startup time consists of the multiple time periods, and the sum of the time periods in length is the length of the startup time of the DC-DC converter, and the startup time is longer than the predetermined period, wherein within the startup time, the comparison circuit compares the output voltage with the predetermined voltage according to the enable signal after the predetermined period, when the output voltage is smaller than the predetermined voltage, the comparison circuit outputs the control signal to stop the DC-DC converter.