| 摘要 |
PURPOSE:To form a temperature detector in a simple structure by connecting a diode in series with a MOSFET, applying a reverse bias to the diode, and connecting the other end of the diode to the GND. CONSTITUTION:A diode 1 and a depression type MOSFET(MOSFET) 2 having a source, a drain and a gate 22 are connected in series. The diode 1 is connected to a buffer 5 in which an FET is used at a midpoint of the MOSFET 2. The buffer 5 has a predetermined threshold voltage. The reverse leakage current of the diode 1 is varied depending upon the square root of temperature, and increased as the temperature rises. When an intermediate voltage Vc of the MOSFET 2 exceeds the threshold value of the buffer 5, it is set to output a signal. Thus, the detection signal of an abnormal temperature can be output, and damage of a power IC can be prevented by controlling it by using the detection signal. |
