Patent ID: 8698484
Filing Date: 2014-04-15
Classification: G01R,H01L

Abstract:
1. An over-voltage and over-temperature detecting circuit for judging whether a temperature exceeds a temperature upper limit or a first voltage exceeds a voltage upper limit, said over-voltage and over-temperature detecting circuit comprising: a voltage-limiting circuit interconnected between a voltage source of said first voltage and a detecting terminal for limiting and controlling the electrical energy magnitude of said first voltage to be transmitted to said detecting terminal through said voltage-limiting circuit; a temperature sensing circuit interconnected between said detecting terminal and a common terminal, wherein the equivalent resistance of said temperature sensing circuit varies with said temperature; a current source connected to said detecting terminal for providing a first current to said detecting terminal, so that a detecting voltage is generated at said detecting terminal; a first comparing circuit connected to said detecting terminal and receiving a first reference voltage value, wherein by comparing the magnitude of said detecting voltage with said first reference voltage value, said first comparing circuit generates a corresponding temperature status signal; and a second comparing circuit connected to said detecting terminal and receiving a second reference voltage value, wherein by comparing the magnitude of said detecting voltage with said second reference voltage value, said second comparing circuit generates a corresponding voltage status signal, wherein if said temperature exceeds said temperature upper limit, said temperature status signal is in an enabling status, and if said first voltage exceeds said voltage upper limit, said voltage status signal is in an enabling status; wherein said voltage-limiting circuit has a limiting voltage value, and if the magnitude of said first voltage increases and is higher than a limiting voltage value, the electrical energy of said first voltage is transmitted to said detecting terminal through said voltage-limiting circuit, so that the magnitude of a second current flowing into said temperature sensing circuit and the magnitude of said detecting voltage increase.