A multiple-dimensional multiple-state SRAM cell using resonant tunneling diodes

Several designs are presented for a multiple-dimensional multiple-state SRAM cell based on resonant tunneling diodes (RTDs). The proposed cells take advantages of the hysteresis and folding I-V characteristics of the RTD. When properly biased, the cell can operate up to (N+1)^m or more number of stable quantized operating states, where N is the number of current-peaks of the RTD and m is the number of access lines. A two dimensional nine-state memory cell has been implemented and demonstrated by a breadboard circuit using two 2-peak RTDs