| 摘要 |
PURPOSE:To improve various characteristics of an amplifier without increasing the value of a current source, by supplying such current according to an input signal that secures almost an equal level for the voltage between both ends of an impedance elements provided between the reference potential point and each control electrode of an output transistor and a cascade transistor. CONSTITUTION:An output transistor (TR)Q1 and a cascade TRQ2 are connected in series between a power source +B and an earth point, i.e. a reference potential point. The 1st impedance element R4 is provided between the earth point and the base functioning as the control electrode of the output TRQ1; and the reference voltage source E and the 2nd impedance element R5 are connected in series between the earth point and the cascade TRQ2. A current supply source 1 is provided to supply the current to both resistances R4 and R5. The source 1 is formed by a circuit such as a current Miller or the like to supply the current so that almost an equal level is secured always for the both-end voltage of the resistances R4 and R5 in accordance with an input signal IN. |
