With the highest value of VC, the state variable can be in SET st

With the highest value of VC, the state variable can be in SET state, where the emulator circuit can be considered a SET resistance. Figure 2c shows the

voltage waveform of V C with respect to time. At the starting point of sinusoidal function of V IN, V C is 1.2 V that is decided by D1 in Figure 1. After the half cycle of sinusoidal function, V C reaches 2.8 V. When one cycle of sinusoidal function is completed, the V C value returns to the value at the starting point of sinusoidal function. Figure 2d shows a typical pinched hysteresis loop of a memristor’s voltage and VX-680 mw current which are emulated by the proposed circuit in Figure 1. In the simulation, V DD is 3.3 V and the frequency of sinusoidal function is 10 kHz. Figure 2 Simulated voltage waveforms. The simulated voltage waveforms of (a) see more V IN, (b) I IN, (c) V C, and (d) the pinched hysteresis loop

of the voltage-current relationship GSK2126458 datasheet of the proposed emulator circuit when the sinusoidal frequency is 10 kHz. The simulated voltage waveforms of (e) V IN, (f) I IN, (g) V C, and (h) the pinched hysteresis loop of the voltage-current relationship of the proposed emulator circuit when the sinusoidal frequency is 40 kHz. Figure 2e, f, g, h shows the simulation results of the proposed emulator circuit with four times higher frequency of 40 kHz than that of Figure 2a, b, c, d, V IN, I IN, V C, and the pinched hysteresis loop, respectively, with 10 kHz. A sinusoidal voltage with 40 kHz that is applied to the emulator circuit is shown in Figure 2e. Here the first three peaks are for increasing V C in Figure 1; thereby, the emulator circuit changes from RESET to SET. The next three peaks are for decreasing the state variable; thus, the emulator circuit can return

to RESET. I IN and V C with the sinusoidal function that is indicated in Figure 2e are shown in Figure 2f, g, respectively. Figure 2h shows the voltage-current Florfenicol relationship of the emulator circuit. In Figure 2h we can see three voltage-current loops at the right and another three voltage-current loops at the left which correspond to the three high peaks and three low peaks in Figure 2e, respectively. Figure 3a shows SET pulses with different amplitude values. Here the amplitude values are increasing monotonically from 0.5 to 3 V. Each SET pulse is followed by a RESET pulse with the fixed amplitude as high as 3 V that is shown in Figure 3b. The state variable that is changed by SET and RESET pulses are shown in Figure 3c. Here V C represents the amount of stored charge at C1 that controls the voltage-controlled resistor in Figure 1 that acts as memristor. Figure 4a shows the read and write circuits for the proposed emulator circuit of memristors [9, 10]. The read circuit is simply composed of a current mirror and comparator. The comparator G1 compares the sensing voltage V SEN with the reference voltage V REF.

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