The effects of carrier-velocity saturation on high-current BJT output resistance

Author

Lee, Sang-Gug ; Fox, Robert M.

Author_Institution

Dept. of Electr. Eng., Florida Univ., Gainesville, FL, USA

Volume

39

Issue

3

fYear

1992

fDate

3/1/1992 12:00:00 AM

Firstpage

629

Lastpage

633

Abstract

Modern bipolar junction transistors (BJTs) tend to operate with saturated carrier velocity in the collector space-charge region. A physical analysis of the effects of velocity saturation on the output resistance of BJTs, especially for high current levels is presented. Physical analyses show that when the collector current density approaches a critical value, the Early voltage can increase significantly due to carrier-velocity saturation as the resulting base push-out partially offsets base-width modulation. This effect is also demonstrated in simulations with PISCES and MMSPICE

Keywords

bipolar transistors; semiconductor device models; BJTs; Early voltage; MMSPICE; PISCES; base push-out; base-width modulation; bipolar junction transistors; carrier-velocity saturation; collector current density; collector space-charge region; high current levels; modelling; output resistance; physical analysis; saturated carrier velocity; velocity saturation; Circuits; Current density; Doping; Electric resistance; Electrons; Frequency response; Operational amplifiers; Thyristors; Transistors; Voltage;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.123488

Filename

123488