Consideration on the Expression of Thyristor-Like Switching Function of PTT with Positive Feedback

Abstract

The notion of Photon Transport Transistor (PTT) similar to Bipolar Junction Transistor (BJT) was announced by IBM in 1989. The PTT is an optical coupling circuit that consists of Light Emitting Diode (LED) and light receiving diode (Photo Diode, PD), where the carrier of the base layer corresponding to that of BJT is light (Photon) only. Later, in 2014, it was reported that the PTT in a positive feedback circuit shows not only an amplification function but also a switching function like thyristor. In this paper, first, we present the thyristor-like operational behavior of PTT in the emitter common circuit by experimentation. Second, based on the experimental results and each VI characteristics of LED and PD, we show the expression of the thyristor-like switching function of PTT and analyze the reason why the PTT has a thyristor-like VI characteristics, from the viewpoint of electronic circuit. Moreover, we discuss the merits of the PTT application, considering the difference between thyristor-like PTT circuit and ordinary thyristor.