Two-dimensional resonant tunneling diode memory cell
AssigneeEpitaxial Technologies
InventorHung Chang Lin
Life of this patent
Estimating the term…
Abstract
Two resonant tunneling diodes with hysteretic folding V-I characteristics are connected in series. The node voltage and the series current of the cell determine the memory state and there can be a large number of states. During writing, one writing pulse sets the pull-down RTD to one of the positive differential resistance region of the hysteretic V-I characteristic, and a second writing pulse sets the pull-up RTD to one of positive differential resistance region. During writing, the series current is sensed by measuring the colon ground current.
Claims8
A memory cell using resonant tunneling diodes(RTD), having folding voltage vs current characteristics with multiple current peaks corresponding to different peak voltages, different valley voltages and multiple positive differential resistance regions, comprising:
- two said RTDs each having at least one peak voltage and at least one valley voltage connected in series;
- one as a pull-up RTD and a second one as pull-down RTD;
- a node at the common joint between said two RTDs;
- an input/output terminal connected to said node for applying a writing voltage to said node and for sensing the node voltage during reading of said memory cell;
- a positive supply voltage terminal connected to the unjoint terminal of said pull-up RTD;
- and
- a low supply voltage terminal having a ground potential connected to the unjoint terminal of said pull-down RTD for sensing the series current through said two RTDs during reading period of the memory cell,
- wherein said RTDs have hysteretic characteristics with more than one said series current for the same voltage across each one of said RTDs.
Dependencies are inferred from the claim text.