Abstract :
The circuit technique known as current-switching is versatile and fundamental to the operation of digital systems working at high digit switching rates. For these reasons, it merits close study by engineering students, particularly those intending to become proficient in circuit design. This paper presents a tutorial-review of the long-tailed pair current-switch using bipolar junction transistors. A brief historical survey sets the scheme in context. Then, a DC characterization, employing a simplified equivalent circuit, is followed by a first-order study of the transient response based on the use of a charge-control model of the transistor. Finally, a miscellany of applications is listed to illustrate the adaptability of the scheme to the design of logic and waveform generation and shaping circuits
Keywords :
bipolar transistor switches; digital systems; electronic engineering education; equivalent circuits; network synthesis; switching circuits; transient analysis; transient response; DC characterization; bipolar junction transistors; charge-control model; circuit design; current-switching principle; digital systems operation; engineering students; first-order study; high digit switching rates; logic circuits; shaping circuits; simplified equivalent circuit; transient response; versatile long-tailed pair; waveform generation circuits; Clocks; Design engineering; Frequency; Logic; Loudspeakers; Monolithic integrated circuits; Receivers; Schottky diodes; Silicon; Switches;
