| 摘要 |
PURPOSE:To stably obtain a temp. detection signal by judging whether chip temp. exceeded temp. set in a circuit system, by changing the base potentials of two transistors corresponding to the variation in chip connection temp. CONSTITUTION:The potential of a connection point (b) rises with the rising in temp. so as to almost follow the temp. variation in the voltage (VBE) between the base and emitter of a transistor (Q)5 whereas the potential of a connection point (a) rises so as to follow the sum of the temp. variations of PN diodes D31, D32 and, therefore, the temp. coefficient of the connection point (a) is steeper than that of the connection point (b). When a transistor Q1 begins to change to a continuity state with the rising in temp., the base potential of a transistor Q2 begins to fall to begin to change to a non-continuity state and the potential of an output terminal 10 begins to rise. When temp. rises to the vicinity of detection temp., the base potential of the transistor Q1 rises at a stroke and the transistor Q2 comes to a non-continuity state at detection temp. at last and the transistor Q1 comes to a continuity state. By this method, the output signal of the output terminal 10 abruptly changes to a high potential signal and a temp. detection signal is obtained. |
