Hello I have been conducting tests on a known 8x8...
# reram
r
Hello I have been conducting tests on a known 8x8 memristor array. I applied a 500ns square pulse at the TE and measured the current at the BE using an oscilloscope. However, instead of observing a gradual increase in compliance current, I am seeing a triangular waveform. A series resistance is connected to the memristor for protection. Do it have to use feedback ammeter mandatory in order to measure compliance current change gradually or can I do it with series resistor Could you offer any suggestions for improving my testing and measurement techniques? https://knowm.com/products/8x8-w-sdc-memristor-crossbar-dip-16
a
> instead of observing a gradual increase in compliance current, I am seeing a triangular waveform The compliance current should be set by your measurement setup, it's not something you measure. I assume you are talking about your measured current, not the compliance current. You can implement a "rough" compliance current with a series resistor. It's difficult to help you improve your test and measurement setup when you have not provided any info on what you are doing. Can you provide: (1) a schematic of your measurement setup, (2) which pulse generator and oscilloscope you are using, (3) a plot of the voltage waveform you are applying, (4) a plot of the current waveform you are measuring
r
@Akash Levy I have attach the files for refrences iam using 48k resistor 500ns pulse of 1v and also trI have attached the files for reference. I am using a 48k resistor with a 500ns pulse of 1V, and I have also tried different amplitudes to achieve a similar output as shown in the screenshot 2025-04-25 174641 from the Rigol DSO5354 oscilloscope. I am using AD3 as the pulse generator. To find the current channel 1 voltage supply- channel 2 series voltage as shown in the schematic diagram in the reference picture for channel 1 and 2 placement For voltage drop in memristor ch1-ch2 For current also i was doing same ch1-ch2
a
Are the devices formed already? Do they require forming? If so, you may be using too small of a voltage. I would start with large pulse width (maybe 10ms) and small amplitude (0.5 V) and increase the voltage to see what effect it has
You also have a fixed pulse train
I would do one pulse at a time
r
It needs forming so I did and got hysteresis loop which was according to the tutorial after forming i was looking for measurement for current for set and reset operation I tried with 50ms also did not work
a
Ok if you've already seen the hysteresis loop from FORMing, that's pretty good. SET/RESET are just the same thing but with lower amplitude and pulse width required
r
Yes for that no expected output is coming
a
Can you show me what you did for FORMing?
r
@Akash Levy Followed this tutorial

https://youtu.be/JYotgUJbPTw?si=Sqao5vzEs8RCEAMZ

got the output shared the picture Sine wave 100hz slowing increase the amplitude by 500mv until hysteresis loop visible
Loop was observed in the waveform software which is used for AD3
a
Great. So now you just need to do it one pulse at a time using increasing amplitude
r
@Akash Levy How do I get the waveform in the picture incremental current if I use the one pulse at a time
@Akash Levy also i want to confirm for current measurement i should do in channel y only for memristor or do i have to do chx-chy?
a
You can measure current by doing
I = V(chy)/Rs = V(chy)/1kohm
How do I get the waveform in the picture incremental current if I use the one pulse at a time
If you want to get the exact waveform in the picture, you might want to try using that exact stimulus. But the voltages might need to be adjusted for the particular RRAM array
For example, you were using 1V SET only. I didn't see you try doing 1V SET and -1V RESET. Where is your RESET pulse train?
r
Yes I have used 1v and -1v but i didn't capture the snapshot of graph for the output With the current probe for the current changes in memristor we have to put in channel y only as per the schematic picture in above message Thank you so much for helping me