GB891229A - Circuit for thermal compensation of transistors - Google Patents

Abstract

891,229. Transistor circuits. ADVANCED RESEARCH ASSOCIATES Inc. Dec. 30, 1958 [Oct. 17, 1958], No. 42096/58. Addition to 874,175. Class 40(6). A composite element having characteristics similar to that of a zener diode or a transistor comprises three transistor stages or a zener diode stage followed by two transistor stages, the last two stages being each stabilized by a transistor arranged between respective emitter and base electrodes and having a floating base electrode. Fig. 1 shows a circuit equivalent to a single NPN common emitter stage and having effective base, emitter and collector terminals B, E and C. It comprises a common emitter NPN stage 38 and common emitter PNP stages 40 and 42 in cascade. The last stages are stabilized by means of auxiliary transistors 60 and 64 connected between the respective emitter and base electrodes and having floating base electrodes, the auxiliary transistors being arranged to pass the collector-base leakage current of the amplifier transistors. Transistor 38 is of silicon type while transistors 40 and 42 are of germanium type having a low surface leakage and a high gain relative to transistor 38. A diode 70 is provided to improve the inverse voltage rating of the input circuit. Figs. 2-6 (not shown) illustrate alternative cicuits equivalent to single transistors of PNP and NPN type with various combinations of common emitter and common collector circuits in the first two stages and with various combinations of PNP and NPN transistors. In Fig. 7 a common base stage followed by two stabilized common emitter stages are arranged to form the equivalent of a single PNPN stage with effective base, emitter and collector terminals B, E and C. Figs. 8, 9 and 10 (not shown) illustrate alternative arrangements providing the equivalent of single PNPN and NPNP stages. In Fig. 11a two stabilized stages are provided and a zener diode is connected across the input of the first stage so that the circuits appear at terminals 300 and 302 as the equivalent of a single zener diode.