| 摘要 |
PURPOSE:To simplify the circuit and circuit integration by utilizing that an impedance value formed via an emitter of a differential amplifier circuit comprising two transistors is multiplied apparently. CONSTITUTION:Transistors (TR) Q2, Q3 form a differential amplifier circuit and TRs Q0, Q9 and Q10 form a current source. A negative feedback current flows to the TRs Q2, Q3 respectively via TRs Q6, Q5, Q1 and TRs Q7, Q8 and Q4. The floating high impedance circuit formed in this way acts like a high impedance element Z' having an input/output current (I1=I2=I) and an impedance of beta1/2XZ (beta1 is the current amplification factor of the TRs Q2, Q3, Q6 and Q7). The floating high impedance is obtained by a simple circuit in this way. |
