| 摘要 |
PURPOSE:To avoid the gain reduction caused by the base bias resistance, by producing the compensating current which offsets the base current of the transistor in the differential amplifying circuit. CONSTITUTION:TR16 having the same polarity and the same characteristics as the collector circuit of transistor (TR)2 for differential amplifier is connected longitudinally to the said collector circuit. In addition, the current amplifier (current Miller circuit) formed by diode 17 plus TR18 having the opposite characteristics to TR2 is connected to the base of TR16. As a result, the compensating current of the same level as the base circuit of TR2 flows to the said base circuit, and thus the compensation signal is generated at base bias supplying resistance 12. With this compensation signal, the effect due to resistance 12 can be offset to avoid the gain reduction. Furthermore, the effect of resistances 15 and 11 can be eliminated by providing the compensating current generating circuit also to TR1. |
