Analysis of the row grounding technique in a memristor‐based crossbar array

Abstract

SUMMARYUsing memristive devices within a crossbar array could pave the way for memories with higher density and speed than state-of-the-art Flash memory, while maintaining relatively low energy. However, memristive crossbar arrays have great difficulty distinguishing logical states because of sneak path currents. The row grounding technique eliminates the sneak path effect, allowing reliable sampling of the memristor state.In this paper, we analyze the row grounding technique and propose several methods and constraints for the design of memristive crossbar arrays. When the row grounding technique is used for these arrays, our analysis shows that increasing the number of rows can help reduce read latency and energy, in contrast to the case of capacitive memory arrays. Simulation results confirm the theoretical analysis proposed in this paper.

Analysis of Memory Matrices with HfO2 Memristors in a PSpice Environment

“…The time diagram of the corresponding voltage signal used for deriving the current-voltage characteristics is presented in Figure 1b for illustration of its magnitude and shape. The corresponding change of the positive integer exponent in Equation (11) in the time domain is also shown Figure 1b for confirmation of the ability of the applied modified Biolek window function to change the exponent in accordance to the memristor voltage and the following change of state variable. The corresponding change of the memristor state variable, x, in the time domain is presented in Figure 1c to illustrate the change of the memristor state in accordance to the applied voltage.…”

“…Figure 1a, containing the experimental i-v relationship and the respective simulated characteristics of the hafnium dioxide memristor, is presented for comparison with the results derived in MATLAB (MathWorks, Natick, MA, USA) [28]. The simulated current-voltage curves are derived by the use of the Lehtonen-Laiho model [20,21] together with the window functions described above-Equations (6), (8), (11) and (13). The modified Joglekar and Biolek window functions together with the used model ensure best proximity between the simulated and the experimental i-v relationship of the memristor.…”

“…The time diagram of the corresponding voltage signal used for deriving the current-voltage characteristics is presented in Figure 1b for illustration of its magnitude and shape. The corresponding change of the positive integer exponent in Equation (11) in the time domain is also shown Figure 1b The simulated current-voltage curves are derived by the use of the Lehtonen-Laiho model [20,21] together with the window functions described above-Equations (6), (8), (11) and (13). The modified Joglekar and Biolek window functions together with the used model ensure best proximity between the simulated and the experimental i-v relationship of the memristor.…”

“…Using the mathematical memristor models described in the previous section and presented by Equations (6), (8), (11) and (13), respective PSpice memristor models were derived and saved in external PSpice libraries. The creation of the respective PSpice memristor schematic starts from the state variable, x, existing in the corresponding window function.…”

“…Its physical realization by HfO 2 , TiO 2 or other modern amorphous metal-oxide materials [5][6][7][8] has geometrical sizes in the nano-range and its power consumption is many times lower than traditional flash memory elements and conventional random access memory (RAM) devices [5][6][7]. These indications are good fundamentals for future applications of memristor crossbars in high-density memories [9][10][11][12]. models based on the described mathematical models are shown in Section 3.…”