| 摘要 |
PURPOSE:To mount a transistor (TR) with no adjustment against variation of hFE even in a hybrid integrated circuit by connecting a resistor between a low potential side of two TRs connected in series in terms of DC and common, driving the base with a constant voltage and applying nearly constant voltage to the base of the other TR though resistance division. CONSTITUTION:A voltage at a connecting point 4 divided by resistors R9, R10 from a power supply 3 is fed to a non-inverting input of an operational amplifier Q5, and since an inverting input is connected to an output terminal, the operational amplifier Q5 acts like a voltage follower outputting a voltage of a terminal 4, and the base of the TRQ1 is driven by a constant voltage. Thus, the current Ic of the TRQ1 is effected slightly by the VBE and depends on the resistance value and the power supply voltage. Further, the voltage division of the TRs Q1, Q2 depends nearly on resistors R1', R2' and the collector-emitter voltage VCE2 of the TRQ2 is decided independently of the collector current Ic. The current and voltage division are determined to a prescribed value with no adjustment against the variance of the hFE of the TR by using the basic circuit in this way. |
