| 摘要 |
<p>PURPOSE:To reduce the current consumption and to attain a stable circuit by connecting a resistor to a differential amplifier in place of a current source supplying its operating current to the differential amplifier circuit. CONSTITUTION:A differential amplifier circuit 6 to which a resistor R2 is connected in place of the use of a constant current source is employed for the output circuit. When a voltage at an output terminal 5 changes negatively (less than Vcc/2), an emitter level of transistors(TRs) Q2, Q3 is decreased and a voltage across the resistor R2 is increased and a circuit I2 flowing thereto is increased. Moreover, when the output is changed positively (more than Vcc/2), the emitter level of the TRs Q2, Q3 is increased and the current I2 is decreased. When the voltage at the output terminal 5 changes positively in this way (no large base current is required for a TR Q7), the current I2 is decreased. Then no undesired current flows, resulting in decreasing the current consumption and the differential amplifier circuit 3 is turned off through the decrease in the current I2 and the possibility of adverse effect such as oscillation of the differential amplifier circuit 3 on other circuits is precluded and the stability of the circuit is improved.</p> |
