| 摘要 |
PURPOSE:To obtain a thermometer which obtains a voltage output exactly proportional to an absolute temperature, obtains a voltage output of low output impedance by a simple circuit, is low in necessary power-supply voltage, and also is scarcely affected by characteristic variations of a semiconductor element, by making a current of different magnitude flow in a fixed ratio to two diodes having p-n junction of the same structure and the same dimensions, and obtaining the voltage proportional to a difference in a voltage drop of both diodes. CONSTITUTION:D1 and D2 are diodes having p-n junction of the same structure and the same dimensions, R1 and R2 are resistances whose resistance ratio is 1/r=R1/R2, and Q, VS and CM are an operational amplifier, +potential of an electric power source and common potential, respectively. One diode D1 is connected between the +potential and the common potential in the forward direction through the resistance R1, and a voltage drop V1 is applied to a non-inverted input terminal of the operational amplifier Q. The other diode D2 is connected between the +potential and an output terminal of the operational amplifier Q in the forward direction through the resistance R2, and the anode is connected to an inverted input terminal. |
