Dynamical Properties and Design Analysis for Nonvolatile Memristor

8/2/2019 Dynamical Properties and Design Analysis for Nonvolatile Memristor

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K Preethesh Shenoy

4DM08EC026

Seminar Guide:

Prima Rodrigues

Yenpo Ho ; Huang, G.M. ; Peng Li


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Introduction

In mathematics Four interconnected

things related in six ways.

Consider q,v,I,.

Fourth mystery element that joins thecapacitor, resistor, and inductor.

Proposed byLeon Chua in 1971.

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Contd

2-terminal device with memristivecharacteristics by S.Williams (2008).

Replace transistors in Future comp, takingmuch smaller area.

Radically different as it carries a memoryof past.

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Memristor Device Characteristics

Memristor- Charge/ Flux controlled.

Charge Controlled: Memristance, =

Flux Controlled: Memductance, =

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Properties & Design Equations

Property 1

= , = 0

Device Resistance: ()

2 Layers of : Pure (Undoped)& Doped with Oxygen Vacancies.

Voltage applied across device,

electric field repels +ve chargedOxygen vacancies thus changing .

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Memory effect since device maintains its

resistivity even if power goes off.

Oxygen vacancies do not movethemselves.

Memristive device resistance:

= .

. 1

Polarity matters in Memristance.

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Property 2

For Charge controlled Memristance,

memristor state controlled by charge throughthe cell & determines ().

= .

.

is the initial state

is the memristor length

is the average ion mobility

is injected charges

Equation valid in the range: - upper limit of effective charge injection - lower limit of effective charge injection.

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Property 3

is only a function of the integrated bias

charge regardless of the waveform shape.

- current source.

Consider , Sinusoidal, - Square wave

By Property 2, w controlled by q. is integral of w.r.t time.

Hence equal change for equal .

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Property 4 If charge injection exerted onto a memristor is a zero net-

charge injection, memristor state will move back to itsoriginal position if .

=

.

. .

=

.

. .

Where . & . is the charge injection bythe positive & negative pulses.

= i.e. original state zero net-charge injection inputs.

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Property 5

For Flux controlled Memristance,

memristor state controlled by flux acrossthe cell & determines ().

=

.

Property 6 is only a function of the integrated bias

voltage regardless of the waveform shape

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Property 7

If the flux injection exerted onto a memristor

is a zero net-flux injection, memristor statewill move back to its original position if .

Similar to property 4.

remains same regardless their waveformshapes as long as the flux injections is same.

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Property 9

In the voltage divider the node voltage

response at node is given by

=

( )

is the voltage at node is the input flux injection is the flux accumulated at node is the flux across memristor .

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Memristor based Memory Circuit

Output Levels logic zero : 0

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Dynamical Properties and Design Analysis for Nonvolatile Memristor