| 摘要 |
PURPOSE:To ensure an effective application of voltage with a low level of power supply voltage, by connecting an element which generates the p-n junction forward voltage between a transistor (TR) forming a differential amplifier and the TRs which are connected in cascode to form an output stage. CONSTITUTION:A differential amplifier is formed with an npn TRs 1-3, and TRs 13 and 14 are connected in cascode to the TRs 1 and 2. Then the TRs 13 and 14 are connected to pnp TRs 15-18 which form an output signal draw-out part, and the output is drawn out to output terminals 25 and 26. A pnp TR28 is connected to the common emitter of the TRs 1 and 2 of the differential amplifier. Then npn TRs 29 and 30 are connected between the emitter of the TR28 and the base of common connection of the TRs 13 and 14 as an element which generates the p-n junction forward voltage. Then the voltage applied to each TR is used effectively with a comparatively low level of power supply voltage +VC. Thus, both linearity and high frequency characteristics of an operational amplifying circuit are improved. |
