| 摘要 |
PURPOSE:To increase the dynamic range of an amplifier circuit by controlling a current flowing to an amplifier circuit with a signal fed back negatively from a negative feedback loop in addition to an input signal and also with said input signal. CONSTITUTION:Each emitter areas of transistors (TR)Q5, Q6 are made equal, each current of constant current circuits CS1, CS2 is set as CS1=CS2=I1, and the resistance value of resistors R3, R6 is set as R6=2R3, then the sum of emitter currents IE1, IE2 is kept to a constant value I1 and the bias current is made stable. When a base current is fed to a TRQ1 from a signal source (ei), since the voltage drop across the resistor R4 has no limit, an output voltage Vout with a large amplitude is obtained across a load resistor R4 and a TRQ3 is not saturated easily.
|
