| 摘要 |
A semiconductor power switch 3 comprises a die mounted on one face of a substrate, and has a temperature sensor 10 on the opposite face of the substrate to monitor the temperature in the vicinity of the switch. The switch 3 is connected between a power source 2 and a load 1 to act as an overcurrent protector. A current sensor 4 and voltage sensor 5 supply signals through an A-D converter 9 to a processor 15 which calculates the power dissipated by the switch 3. The processor calculates the temperature at points in the switch die from the measured temperature and the dissipated power, using a look-up table and an algorithm. If the highest calculated temperature exceeds a preset limit, the switch 3 is opened or another device is actuated to prevent damage. |
