| 摘要 |
PURPOSE:To obtain a differential output amplifier having the capacity for operating at a low voltage and a broad dynamic range by connecting emitters of output transistors (TRs) of two sets of current mirror circuits by a resistor and connecting an input of the one circuit to a bias means. CONSTITUTION:When an input signal DELTAIIN from an input terminal IN is larger, a current flowing to a TRQ13 and a resistor R14 is large, a base potential of one output TRQ11 is increased and one output current Iout1 is increased. Although the potential at an emitter terminal 11 is increased, since the base potential of the other output TRQ12 is constant, the potential at an emitter terminal 12 is kept constant and the other output current Iout2 has a decrease by the share corresponding to the increase in the current flowing from the emitter terminal 11 via a resistor 11, thereby obtaining a differential output. Only one stage of the TR exists between the power supply lines, then the low voltage operation is attained and a low distortion factor is attained by setting the voltage drop of the emitter resistor larger than the fluctuating component of the potential between the base and emitter. |
