Multivalued SRAM cell using resonant tunneling diodes

A multivalued SRAM cell using a vertically integrated multipeak resonant tunneling diode (RTD) pair is described. Two RTDs in series can have 2N+1 stable states. With this concept, a five-stable-state memory cell has been implemented with two 2-peak RTDs. Several designs are presented for a high-speed static random access multivalued memory using the folding characteristics of RTDs. The different designs are described and studied by comparing their power consumption under different conditions of device parameters and switching speed. The authors show that the proposed memory cell using a pair of multipeak RTDs yields the best result from the standpoint of size, power dissipation, and speed among the RTD memory cells discussed