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The Transistor as Low Level Switch

Abstract

The common collector transistor switch has in the on state with open emitter a certain offset voltage U{sub EK} {approx_equal} -kT/qB{sub N}. This expression is derived in a new, more physical way. It is further shown at which emitter current the current amplification factor B{sub N} should be measured to get a correct value for the above expression. The collector current I at zero collector voltage I{sub K} = I{sub 0}(exp(qU{sub E}/kT) - 1) extremely well. Substitution of I{sub EBO} and I{sub KBO} by I{sub 0} in Eber's and Moll's relations consequently improves these equations and the characteristics of the transistor switch can be better determined. At switching on and off transients appear across the switch. The influence of the 'spike' at switching off can be described by an current I{sub SPIKE} which is easy to calculate. I{sub SPIKE} is approximately dependent only on the base - emitter depletion layer capacitance and the chopper frequency f{sub 0}. Some compensated switches have lower drift than the drift in U{sub EK}. They may, for example, have a temperature drift < 0.2 {mu}V/deg C and a long time drift < 2 {mu}V/week. Some compensated switches also have I{sub SPIKE} < 10{sup -12} f{sub  More>>
Authors:
Publication Date:
Oct 15, 1963
Product Type:
Technical Report
Report Number:
AE-121
Resource Relation:
Other Information: 14 refs., 16 tabs.
Subject:
47 OTHER INSTRUMENTATION; SWITCHES; TRANSISTORS; COMMUTATORS
OSTI ID:
20930950
Research Organizations:
AB Atomenergi, Nykoeping (Sweden)
Country of Origin:
Sweden
Language:
English
Other Identifying Numbers:
TRN: SE0708362
Availability:
Commercial reproduction prohibited; OSTI as DE20930950
Submitting Site:
SWDN
Size:
64 pages
Announcement Date:
Oct 01, 2007

Citation Formats

Lyden, Anders. The Transistor as Low Level Switch. Sweden: N. p., 1963. Web.
Lyden, Anders. The Transistor as Low Level Switch. Sweden.
Lyden, Anders. 1963. "The Transistor as Low Level Switch." Sweden.
@misc{etde_20930950,
title = {The Transistor as Low Level Switch}
author = {Lyden, Anders}
abstractNote = {The common collector transistor switch has in the on state with open emitter a certain offset voltage U{sub EK} {approx_equal} -kT/qB{sub N}. This expression is derived in a new, more physical way. It is further shown at which emitter current the current amplification factor B{sub N} should be measured to get a correct value for the above expression. The collector current I at zero collector voltage I{sub K} = I{sub 0}(exp(qU{sub E}/kT) - 1) extremely well. Substitution of I{sub EBO} and I{sub KBO} by I{sub 0} in Eber's and Moll's relations consequently improves these equations and the characteristics of the transistor switch can be better determined. At switching on and off transients appear across the switch. The influence of the 'spike' at switching off can be described by an current I{sub SPIKE} which is easy to calculate. I{sub SPIKE} is approximately dependent only on the base - emitter depletion layer capacitance and the chopper frequency f{sub 0}. Some compensated switches have lower drift than the drift in U{sub EK}. They may, for example, have a temperature drift < 0.2 {mu}V/deg C and a long time drift < 2 {mu}V/week. Some compensated switches also have I{sub SPIKE} < 10{sup -12} f{sub 0}A. The static offset current in the off state can easily be made < 10{sup -12} A.}
place = {Sweden}
year = {1963}
month = {Oct}
}