| 摘要 |
PURPOSE:To process a comparatively large signal voltage with good linearity by compensating the difference of a base-emitter voltage caused by the imbalance of transistors (TR) by the base-emitter voltage of a TR pair in the similar imbalanced state. CONSTITUTION:When an input voltage (VB3-VB4) at input terminals 30, 40 is large, the conversion current flowing to an emitter impedance 7 is large and the base-emitter voltages of the TRs 1, 2 have a difference. In this case, the ratio of emitter currents IE3, IE4 of TRs 3, 4 is controlled to be equal to the ratio of emitter currents IE2, IE1 of the TRs 2, 1. Then a conversion current (IE1-IE2) proportional to the input voltage (VB3-VB4) is obtained without error. Thus, a comparatively large signal voltage is processed with high linearity.
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