Title :
Equivalent circuit and ECL ring oscillators of graded-bandgap base GaAs/AlGaAs HBTs
Author :
Yamauchi, Yuji ; Ishibashi, Takayuki
Author_Institution :
NTT Electrical Communications Laboratories, Atsugi, Japan
Abstract :
Equivalent circuit parameters of graded-bandgap base GaAs/AlGaAs heterojunction bipolar transistors are derived by analysing static and microwave characteristics. Here, the estimated base transit time of 1.4 ps indicates that the average electron velocity is enhanced under the built-in field of the graded base. Additionally, ECL ring oscillators are simulated using the obtained parameters. The simulated propagation delay time of ECL gates agrees well with an experimental result of as short as 65 ps/gate.
Keywords :
III-V semiconductors; aluminium compounds; bipolar transistor circuits; bipolar transistors; emitter-coupled logic; equivalent circuits; gallium arsenide; logic gates; semiconductor device models; ECL gates; ECL ring oscillators; GaAs/AlGaAs heterojunction bipolar transistors; base transit time; built-in field; electron velocity; equivalent circuit analysis; graded-bandgap base; microwave characteristics; propagation delay time; simulation; static characteristics;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19860012
