| 摘要 |
905,945. Transistors. SOC. SUISSE. POUR L'INDUSTRIE HORLOGERE S.A. Dec. 17, 1958 [Dec. 28, 1957], No. 40796/58 Class 37. [Also in Group XL (c)] In a transistor with two base electrodes disposed at different distances from the emitter the electrodes are so positioned that in response to an increasing base-collector reverse bias the collector space charge region expands to increase the resistance of the current path between one of the base electrodes and the emitter junction without materially altering the resistance of the path from the emitter junction to the other base electrode. In one embodiment, Fig. 2, the base electrodes b 1 and b of a junction transistor are in the form of concentric annuli disposed on opposite sides of an annular groove surrounding the emitter E. In operation, the collector voltage may be increased until the associated space charge region extends as shown by the broken line to the base of the groove to isolate base b from the emitter without appreciably affecting the resistance between the emitter and base b 1 . In an alternative arrangement (Fig. 3) in which the groove is dispensed with, the inner base electrode b 1 and emitter are disposed on a thickened part of the base region. A further alternative shown in Fig. 5 is to mount the emitter and inner base electrode on a region of much lower resistivity than the remainder of the base zone into which the space charge region will only slightly penetrate. In the device shown in Fig. 4, two additional annular zones C 1 , C 2 of the same conductivity type as the collector zone C are provided which are electrically connected to the collector electrode proper. As the collector bias is increased the resistance of the channel between these annular zones is increased until the base electrode b is isolated. The transistors described may be used in bi-stable multivibrator circuits (see Group XL (c)). |
