| 摘要 |
An overcurrent detection/protection apparatus protects a switching element (T 11 ) from an overcurrent. When a current flows through the switching element, a voltage drop occurs. The apparatus amplifies the voltage drop and generates a first voltage (V 15 ). And, the apparatus divides a voltage at a node between the switching element and a load and generates a second voltage (V 14 ). If the first voltage exceeds the second voltage, the apparatus concludes that there is an overcurrent. Due to wiring inductance (L) and the ON resistance (Ron) of the switching element, the second voltage decreases when an overcurrent flows. Accordingly, the apparatus can instantaneously detect an overcurrent, which may be caused by a dead short, and rendering the switching element inoperative, to thereby protect the switching element and wiring between the switching element and the power source. The apparatus employs no shunt resistors, and therefore, is compact and low-cost. |
