Patent ID: 6441679
Filing Date: 2002-08-27
Classification: H03K

Abstract:
A semiconductor active fuse comprising:a first semiconductor element having a first main electrode connected to a DC power supply outputting supply voltage higher than 12V, a second main electrode connected to a load, and a control electrode; a second semiconductor element having a first main electrode connected to the first main electrode of the first semiconductor element, a second main electrode connected to a reference circuit, and a control electrode connected to the control electrode of the first semiconductor element; a comparator having a high-potential power supply terminal, a low-potential power supply terminal, a first input terminal electrically coupled to the second main electrode of the first semiconductor element, and a second input terminal electrically coupled to the second main electrode of the second semiconductor element; a driver for supplying a control voltage to the control electrodes of the first and second semiconductor elements according to the output of the comparator; a first diode having a first cathode connected to the first input terminal and a first anode connected to the low-potential power supply terminal; a second diode having a second cathode connected to the second input terminal and a second anode; and a resistor having one end connected only to the second anode and the other end connected both to the first anode and to the low-potential power supply terminal, wherein, if an overcurrent that is above a reference current determined by the reference circuit flows through the first semiconductor element, the semiconductor active fuse turns on and off the first semiconductor element to produce current oscillations that cut off a conductive state of the first semiconductor element.