By Mi Lin, Wei-feng Lyu and Hai-peng Zhang, Hangzhou Dianzi University, China
Circuit design based on the negative differential resistance (NDR) characteristic has more recently attracted a lot of research. NDR is a property of some circuits and devices in which an increase in voltage across the device results in a decrease in current through it. The most popular device with NDR characteristic is the resonant tunneling diode (RTD). It is made of two undoped wide-bandgap-semiconductor barrier layers, sandwiching an undoped well-layer made of narrower bandgap semiconductor, with heavily doped contact layers on the outer surfaces. The physical structure and NDR characteristic of the RTD determine its application and robustness in designs, including multiple-valued logic (MVL) circuits.
Here, we propose an RTD in a novel multiple-valued NDR T flip-flip that simplifies circuit design with fewer components.
The tri-valued T flip-flop, the ternary JK flip-flop and the D flip-flop create a complete ternary NDR flip-flop series, providing a wealth of ideas and design methods for MVL-type circuits.