Memristor: Modelling and Applications

1. Memristor: Modelling and Applications Amit Kulkarni Nguyen Hoang

2. Content • What is memristor? • Prediction of memristor • Mathematicalequations • Physical Implementation • Pinched hysteresis loop • SPICE model • Write circuit • Read circuit • Challenges and Applications • Summary Chalmers university of Technology DAT175 Topics in Electronic System Design

3. What is memristor? • Two terminal passive electrical component • Memorize the charge flow • Change the resistance • Symbol: Chalmers university of Technology DAT175 Topics in Electronic System Design

4. Leon Chua’s prediction of existence of Memristor Dr.Leon O. ChuaUniversity of California, Berkeley Chalmers university of Technology DAT175 Topics in Electronic System Design

5. Mathematical equations of memristor ‘w’ is a state variable Chalmers university of Technology DAT175 Topics in Electronic System Design

6. Physical implementation Dr.R. Stanley Williams HP Labs(Quantum science) Chalmers university of Technology DAT175 Topics in Electronic System Design

7. State equations of implemented memristor Chalmers university of Technology DAT175 Topics in Electronic System Design

8. Pinched hysteresis loop Courtesy: Massimiliano Di Ventra, Yuriy V. Pershin, and Leon O. Chua.Publication: Circuit Elements With Memory: Memristors,Memcapacitors, andMeminductors Chalmers university of Technology DAT175 Topics in Electronic System Design

9. SPICE model • State equation:  Chalmers university of Technology DAT175 Topics in Electronic System Design

10. SPICE model (1) • Port equation:  Chalmers university of Technology DAT175 Topics in Electronic System Design

11. SPICE model (2) • Full model: Chalmers university of Technology DAT175 Topics in Electronic System Design

12. Write circuit • Decision levels • Circuit Chalmers university of Technology DAT175 Topics in Electronic System Design

13. Write circuit(1) • Write logic – 0 • Write logic – 1 Chalmers university of Technology DAT175 Topics in Electronic System Design

14. Write circuit(2) • Express flux in terms of state variable • Ideal case: • logic-1 at level 1 • logic-0 at level 0 Chalmers university of Technology DAT175 Topics in Electronic System Design

15. Write circuit(3) • Applying to ideal case Chalmers university of Technology DAT175 Topics in Electronic System Design

16. Read circuit IEEE/ACM International Conference 2009 (from HP) IEEE/ISCAS International Symposium 2011  State perturbation may occur! Chalmers university of Technology DAT175 Topics in Electronic System Design

17. Read circuit (1) • State perturbation: • State level changes while applying voltage for reading • Memristor is charge-dependent How to avoid/reduce? • Complementary-charge • circuit Chalmers university of Technology DAT175 Topics in Electronic System Design

18. Read circuit (2) • Influence of complementary charge on state stability Chalmers university of Technology DAT175 Topics in Electronic System Design

19. Read circuit (3) • Influence of complementary charge on state stability 500,000 times 10,000 times Chalmers university of Technology DAT175 Topics in Electronic System Design

20. Read circuit (4) • Outputs of logic 0 and 1: Chalmers university of Technology DAT175 Topics in Electronic System Design

21. Challenges of the research • Control state stability • For write and read circuits • For other applications Chalmers university of Technology DAT175 Topics in Electronic System Design

22. Applications • Non-volatile memory • Up to 100Gbits/cm² • Crossbar switch • LUT Chalmers university of Technology DAT175 Topics in Electronic System Design

23. Summary • Memristor can remember amount of charge goes through it via its varied resistance • SPICE model is made for circuit-level research • Read-write circuits are built • Challenge in applications: state stability • Vast of applications Chalmers university of Technology DAT175 Topics in Electronic System Design

24. Thank you for your attention! Chalmers university of Technology DAT175 Topics in Electronic System Design