| 摘要 |
PURPOSE:To widen the dynamic range of an input differential voltage and to improve noise performance and frequency characteristics by using such plural differential amplifying circuits that the 1st and the 2nd input terminals are connected to one terminal of an AC input signal source and respective output terminals are connected in common. CONSTITUTION:This differential amplifier is constituted by being equipped with transistors (TR) Q1-Q6, resistances RL1 and RL2 which are equal in resistance value to each other, resistances R1-R5, capacitors C1-C4, constant current sources CS1-CS3 which all supply a current I0, and a constant voltage source VS1. Then, a differential amplifying circuit which has the TRs Q1 and Q2, a differential amplifying circuit with the TRs Q3 and Q4, and a differential amplifying circuit with the TRs Q5 and Q6 share the resistances RL1 and RL2 and are connected in parallel. A current I01 which is the sum of currents I1, I3, and I5 and a current I02 which is the sum of currents I2, I4, and I6 are determined by output voltages V01 and V02, so the dynamic range of an input voltage Vi1 is about a voltage 2VB wider than a conventional example as shown in figure. |
