| 摘要 |
PURPOSE:To decrease and miniaturize the number of components and to execute the output signal with high accuracy by extracting and switching a potential high at two times as much as the voltage between base emitters and the potential low for the voltage between base emitters from the output of an operational amplifier. CONSTITUTION:To the base of an output transistor TrQa of an operational amplifier OP1, a diode Qc is connected and a potential V1 high at two times as much as the voltage between base emitters is generated from an output V0 of the OP1. The voltage converts the output signal more than the voltage of a reference voltage source Vref out of the output signals of the OP1 to a current Ia by a resistance R1 and a TrQ2 through a TrQ1 and is outputted from an output edge Vab through a current mirror circuit composed of TrQ4, TrQ5 and resistances R3 and R4. Next, when the input of the OP1 is decreased to a reference voltage, the TrQ1, TrQ2 are turned from ON to OFF, a TrQ3 is turned on, and a base potential V2 of an output TrQb is converted to a current Ib by the TrQ3 and a resistance R2. Thus, since currents Ia and Ib are automatically switched, the number of the components is reduced, a device is miniaturized and the output signal can be executed with the high accuracy. |
