GB753015A - Improvements in or relating to transistor circuit arrangements - Google Patents

Abstract

753,015. Transistors. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Jan. 8, 1954 [Jan. 13, 1953], No. 597/54. Class 37. [Also in Group XL (c)] A circuit arrangement comprises a four-zone transistor system having the junctions between the first and second and between the second and third biased in the forward direction, and that between the third and fourth zones in the blocking direction. The term " four-zone transistor system " means either a transistor having at least four successive zones of alternately opposite conductivity types, as shown in Fig. 1, or the equivalent combination of two threeelectrode transistors as shown in Fig. 2. In Fig. 1, the width of each of the middle N and P zones 2 and 3 is less than the diffusion length of minority carriers in the zone. Zone 1 comprises emitter e, zone 4 comprises collector c. The junctions between these zones and their adjacent zones are biased in the forward and reverse directions respectively, and that between 2 and 3 in the forward direction. The arrangement is equivalent to that shown in Fig. 2 in which the base 211 and collector 3<SP>11</SP> zones of one three-electrode transistor are connected to the emitter 2<SP>1</SP> and base 3<SP>1</SP> zones of a second transistor. Input signals from source 5 may be applied to emitter e or base electrode b and appear in amplified form in load 8 in the collector circuit. The arrangement is such that the base resistance rb provides negative feedback. A modification as shown in Fig. 4 in which two additional zones 15, 16 are provided in front of the four-zone arrangement 11, 12, 13, 14 of Fig. 1. The junction between zones 15 and 16 is biased in the forward direction, and that between 16 and 11 in the reverse direction. In effect this provides a third transistor consisting of emitter base and collector zones corresponding to zones 15, 16 and 11 respectively. Specification 747,695 is referred to.