TRANSISTORS IN SWITCHING CIRCUITS 12-19 



as high as 1000 cj^cles in tests on the transistor of Fig. 1 . Transistors 

 have been inchided in plastic embedded ciicuils without cliangc of 

 fliaracteristics. 



SUMMARY -TRAN'SISTOR l'R< )l'KKr[ KS 



Transistors have been designed witli properties expressly intended 

 for switching applications.* The characteristics are acceptable for con- 

 temporary switching type eii'cuits and sufficiently reproducible to per- 

 mit interchangeability of devices in circuits of normal reciuirements. 

 The characterization has been sufficiently unique to permit the calcula- 

 tion of first order circuit performance. The characterization is not suffi- 

 ciently complete to permit determination of the complete transient 

 behavior. 



In terms of the circuits described, the major parameter limitation is 

 concerned with the ^■ariability of the d-c collector resistance among 

 units and with temperature. It is expected that future circuit develop- 

 ment will place additional rerjuirements on the transistor, particularly 

 as related to the transitions between regions. It is also to be expected 

 that future circuit designs may establish new or modify present device 

 requirements. 



A major consideration for computer or computer-like systems, re- 

 liabilitj^, particularly with respect to time and temperature, has not 

 been established, but appears to be favorable. 



ACKNOWLEDGMENT 



It is impossible to properly acknowledge credit to all of those who 

 contributed to the concepts, data and results of this paper. Particular 

 acknowledgment is due to J. A. Morton who provided first the method 

 of attack for the analysis and second, continued stimulation. Acknowl- 

 edgment is also given to A. J. Rack who first classified and explained 

 the several simple circuits of the first section. J. J. Kleimack provided 

 transistor data and R. L. Trent, circuit data. 



* See Reference 3 also. 



