SOAP Board
We identify several programming technique of memristors. To measure & compare these methods we develop simple board. The main board requirement is simple, offering several configuration memristors’s mode and in second step using the programmed memristors into a simple electronic function.
The simple electronic function for SOAP is simple gain amplifier ajustement. Depending on SOAP results a second project will be launched around multistage analog filters.
The different programming methods are
- Classic Resistor
- Current Mirror ( REF2000/OPA602 ; LT1990 ; discrete MOSFET )
- Active programming as described in High precision analogue memristor state tuning DOI:10.1049/el.2012.2295 http://dx.doi.org/10.1049/el.2012.2295
- Bridge programming as described in A bridge technique for memristor state programming DOI:10.1080/00207217.2019.1692371 https://doi.org/10.1080/00207217.2019.1692371
The targeted memristor for this board is a tungsten or Carbon SDC in DIL16 from Knowm inc and the global development environment is Digilent AD2 Platform.
The block diagram is the following
![](http://www.conceptualise.be/wp-content/uploads/2020/09/image-1024x830.png)
SOAP Layout V1
![](http://www.conceptualise.be/wp-content/uploads/2020/09/image-1.png)
SOAP V1 Results are quite positives :
- Current mirrors topologies are NOT appropriate to program SDC memristors. A voltage-lock in effect was observed each time , which makes a precise programming value very difficult. (Voltage lock-in occurs when the resistance of the device falls below a limit where the current-limited drive circuitry cannot apply a sufficient negative voltage to overcome threshold)
- The topology described by “Active programming as described in High precision analogue memristor state tuning DOI:10.1049/el.2012.2295 ” doesn’t fit with our requirements. Negatives pulses generates erase therefore no long period of stable resistor
- The topology described by “Bridge programming as described in A bridge technique for memristor state programming DOI:10.1080/00207217.2019.1692371″ looks promising . We got positive results but due to not precise data sheets of ALDxxx MOSFET we decided to adjust the design.
SOAP Layout V2b
Board specifications are
- Three configurations methods:
- Classic Resistors (CONF1)
- Transimpedance topology as described in DOI:10.1109/ACCESS.2019.2915100 (CONF2) https://ieeexplore.ieee.org/abstract/document/8708254
- Bridge programming as described in DOI:10.1080/00207217.2019.1692371 (CONF3) https://doi.org/10.1080/00207217.2019.1692371
- Antiserial configuration allowed on 4 memristors
- Precise onboard measurement of Memristor’s Voltage & Current
- Memristors & CONF/APP mode selection by Waveforms interface (AD2)
![](https://www.conceptualise.be/wp-content/uploads/2021/01/20210118_103107-2-1024x498.jpg)
![](https://www.conceptualise.be/wp-content/uploads/2021/01/Screenshot-2021-01-19-at-17.03.35.png)
![](https://www.conceptualise.be/wp-content/uploads/2021/01/C1UIPlot_81006.png)
![](https://www.conceptualise.be/wp-content/uploads/2021/01/C2UIPlot_81006-2.png)
![](https://www.conceptualise.be/wp-content/uploads/2021/01/C2SRPlot_81004s-2-1024x631.png)
The SOAP 2139V2b is ready for production, don’t hesitate to contact us for a quotation.
JP Guarrera – Manager & Principal Engineer jp.guarrera@conceptualise.be