| 摘要 |
PURPOSE:To measure the reference voltage with high accuracy, by adding a transistor having the collector, base and emitter connected to a power supply terminal of the high potential side, a reference input terminal and an input terminal respectively. CONSTITUTION:The potential of a terminal 2 is higher than that of a terminal 6, and the difference of potential between these two terminals is larger than the forward voltage VBE between the base and the emitter of a transistor TRT5. As a result, the TRT5 is active. Thus the potential of a terminal 1 is lower than the reference voltage Vref applied to the terminal 2 by a degree equal to the voltage VBE. In this case, the potential of the terminal 1 is lower than that of the terminal 2, and therefore a TRT1 is turned off. Then all of the emitter currents of the TRT5 flow to a resistance R6. As a result, it is possible to obtain the voltage Vref by measuring the voltage V emerging at the terminal 1 and then adding the voltage VBE of the TRT5 to the voltage V. |
