| 摘要 |
PURPOSE:To ensure a zero detected current when a chip temperature is lower than a specified value and to generate an approximately linear detected current at or above the specified value, by connecting first and second current mirror circuits to temperature detecting transistors. CONSTITUTION:A collector current i2 of a transistor 16 in a temperature detecting part 3, which is controlled by a reference voltage generating circuit 2, is changed with a temperature. The current i2 is nonlinearly changed in a low temperature range based on the characteristics of the transistor. A first current mirror 5 is connected to the output side of the transistor 16. When the current i2 is smaller than an output current I3 of the circuit 5, a current i4 to a second current mirror circuit 6, which is connected to the output side of the circuit 5, becomes zero, and an output current i5 of the circuit 6 becomes zero. Meanwhile, when the temperature is increased and the current i2 becomes larger than the current I3, a current (i2-I3) is applied, and the current i5, which is changed approximately linearly, is outputted from the circuit 6. When a chip temperature is lower than a specified value, the detected current becomes zero without fail. When the temperature is at or above the specified value, the temperature detection current, which is changed approximately linearly, is obtained. |
