| 摘要 |
1,238,204. Transistor circuit. SOC. GENERALE SEMICONDUTTORI S.p.A. 25 Sept., 1968 [21 Dec., 1967], No. 45585/68. Heading H3T. Saturation of a switching transistor T 1 , Fig. 2, is controlled by a control transistor T 2 whose base is connected through a resistor R B to its collector and this is connected to the base of T 1 , whose emitter is connected through a resistor R E to the emitter of T 1 , the combination forming a three terminal unitary construction B, C, E. The device may be integrated (Fig. 3, not shown). Transistor T 2 may have a collector resistor (RC, Fig. 5, not shown) which provides a limit to the range of control of T 2 which saturates when its collector current reaches a value dependent upon the resistor (Rc). A capacitor (C B , Fig. 6, not shown) by-passes the base emitter junction of T 2 to improve switch-on speed. When the transistors are formed in the same semi-conductor chip, their characteristics, especially #, are closely correlated and T 2 provides optimum compensation for changes in gain of T 1 , which affect the saturation of T 1 , over a wide temperature range. |
