The memristive system behavior of a diac

The memristor was introduced as a nonlinear circuit element in 1971, and systems showing memristor-like properties such as zero-crossing hysteresis loops were described in 1976. In 2008, a thin-film system that behaved like a memristor over some part of its operating region was discovered. Memristors and memristive systems have thus become a hot research area in recent years, making it important to discover and study such systems that show memristive behavior. Memristors and memristive systems exhibit three distinguishing characteristics that are known as their three fingerprints. Discharge lamps were also shown to exhibit memristive behavior recently. The diac, an electronics component commonly used in alternating-current (AC) applications, exhibits a breakdown mechanism similar to that observed in discharge lamps. According to textbooks, a diac should also obey the characteristics of a memristive system. In this work, a phenomenological model for a diac is first presented, and it is shown that this model satisfies the description of a memristive system; circuit simulations are also used to verify the memristive system behavior of a diac. However, experiments performed on a DB32 diac reveal that it only behaves like a memristive system in a narrow frequency range around 1 kHz. The effect of the junction capacitances of the diac are found to be important in this regard, resulting in the deviation of the diac from the expected memristive system behavior, as supported by the model and circuit simulations. We also believe that the reverse recovery current at frequencies above 1 kHz inhibits the zero-crossing behavior of the diac, even though its hysteresis curve is very similar to that of a memristive system.