| 摘要 |
PURPOSE:To form easily a differential amplifier passing a DC signal and having a wide dynamic range by connecting a part or all of inputs/outputs of n-set of differential amplifier pairs whose gain and linear region differ from each other in common so as to constitute a compression amplifier. CONSTITUTION:Collectors of the n-set of differential transistor (TR) pairs comprising TRsQ1, Q1'-Qn, Qn' are connected in common, further an input 1 IN1 is connected in common with bases of the TRsQ1-Qn and an input 2 IN2 is connected in common with bases of the TRsQ1'-Qn'. In connecting a load impedance ZL in common with each differential pair with an input amplitude of a prescribed value, as the emitter impedance is increased, the current change rate of the differential pair is smaller and the gain is smaller, while the linear region is widened. When the input amplitude is larger to a degree the, the gain G1 of the TRsQ1, Q1' is saturated, the gain G2 of the next TRsQ2, Q2'- the gain Gn of the TrsQn, Qn' are still in the linear region and the gains are larger than the gain G1. Thus, the output with respect to the input is being compressed as the input amplitude is increased. |
