Temperature Compensation Circuit for ISFET Sensor
Round 1
Reviewer 1 Report
Thanks for your contribution. In my opinion, the work described in paper can be considered a good engineering exercise, that provide the expected performance, as demonstrate the simulations that have been carried out.
In the following I summarize some observations and suggestions that I am sure they will help to improve your contribution:
In section 4:
1. Figure 11 is mentioned in line 298 and 353, but this figure is not in the paper.
2. I suggest to include a figure that connect the circuits in Figure 12 and Figure 14.
3. Line 260 says: The circuit shown in Figure 12 is the proposed by Irena [36]”. This is the basic circuit used in pH measurement, but I have not be able to find this circuit in the reference 36. May be is a reference number mistake? What is the novelty in the proposal?
4. Line 278: where is said “... with Vt1 and ...” should say “... with V*t1 and ...” On the other hand, in this paragraph the notation ΔpH is a little confusing because I think that it is named VpH, in line 286. Are both naming the same magnitude?
5. In Figure 13 a) Vout versus pH is represented, but in the figure caption says VpH. The same happen on figures 15 y 16. Please revise this notation and the font size in order to improve the figure uniformity.
6. Eq. 14 uses the voltage VTReFET y VTISFET, but they are not mentioned before; on the other hand in figure 14, they are named V1 and V2 respectively. Please clarify that, and how eq. 15 is obtained.
7. In line 318, I think that where is said “According to 18 ....” should say “According to 17 ....”
8. I suggest the comparative study in tables 5 and 6 included at the end of this section, could be moved and included in a new section name discusion.
9. The references 44, 45, 46, are incomplete, so they should be completed.
10. Line 340 and 343: spelling mistake in “componsation” and “predecte”
In section 2.1
1. In order to mantain uniformity in the figure 4, I suggest represent the data, simulated and experimental, in the same order and, if it is possible, using the same symbols.
2. In line 153, it is reported an error about 0,32% for pH=3. Is it the worst case? Are the error for the other solutions below this value? Please clarify it.
3. In Table 1, I think there is a mistake in lo units. Please review.
4. What is the temperature at which the parameters of table 6 that depend on it, have been estimated ?
5. Figure 5 caption. pH 3 is mentioned, but not used in data. It should be removed.
6. In Figure 6. The regression curve should be included, given that the slope of this curve is the sensitivity. On the other hand, the experimental data in this figure pH [3,7,11] are not the data presented in Figure 5. Please carify it.
In section 3.1
1. Please clarify the origin of Figure 7 and Figure 8. It seems to me that Figure 7 is a theoretical result, and Figure 8 is obtained by simulating the ISFET model. Is it that way?
2. I think table 3 and table 4 are redundant because the data provided in both table are printed in figure 8 y 9 respectively. Note also that there are discrepancy between them.
I encourage the authors to keep on working and improve their manuscript.
Author Response
Ms. Ref. No.: jlpea-646455
Title: Temperature compensation circuit for ISFET sensor
Journal of Low Power Electronics and Applications
Dear Reviewer,
Thank you for reviewing my manuscript and for paying much attention to its content. Your comments were so consistent. I would like to inform you that the manuscript was revised according to your suggestions. So, the revised version should be more suitable for the reader. You find the final form in attachment.
Here, some response to your comments. I look forward to receiving your reply.
Best regards,
Ahmed GADDOUR
National School of Engineering of Monastir
Tel.: +216 50 998008
E-mail: [email protected]
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Responses for reviewer #1 |
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Comment 1:
Response: |
“Line 260 says: The circuit shown in Figure 12 is the proposed by Irena [36]”. This is the basic circuit used in pH measurement, but I have not be able to find this circuit in the reference 36. May be is a reference number mistake? What is the novelty in the proposal?”
Thank you Sir, I checked the reference [36] and it’s correct, I think you didn’t find the circuit because the thesis is written in French, so about your question “What is the novelty in the proposal?”, the author present a circuit based on deferential measurement and he used two amplifier AD8542 so this circuit is a bit bulky. The one of many novelty of this work is to replace the two amplifiers AD8542 by two OTA low consumption amplifiers, as I said in the manuscript we try to present a circuit that is suitable for ISFET Array. In addition, in this this work we developed a new demonstration with a simple manner of how ISFET/ ReFET can reduce the temperature. In the literature, we can found only one demonstration about temperature cancelation using ISFET/ReFET topology, exactly in ref [25] , but in this work we give a new and simpler demonstration about how the temperature can be canceled when we use the ISFET/ ReFET topology, the results of the demonstration (9.43 where compared with the simulation (5 ) and we found that the simulation and the demonstration have some concordance.
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Comment 2:
Response: |
“how eq. 15 is obtained?”
In reference [43] this equation describe the threshold of the ISFET as a function of temperature
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Comment 3:
Response |
“In line 153, it is reported an error about 0,32% for pH=3. Is it the worst case? Are the error for the other solutions below this value? Please clarify it.”
No actually is the best case, the worst case is for pH=11.01 which is bout of 1.12 %.
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Comment 4
Response |
“What is the temperature at which the parameters of table 6 that depend on it, have been estimated ?”
The temperature range is from 0°C to 50°C
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Comment 5
Response
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“The experimental data in this figure pH [3,7,11] are not the data presented in Figure 5. Please carify it”
In figure 5 we used our validated ISFET macro model , for pH= 3 we used approximately a 1000 point for each value of a pH, by the way we present in figure 5 a new method for threshold extraction,
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Comment 6
Response |
“Please clarify the origin of Figure 7 and Figure 8. It seems to me that Figure 7 is a theoretical result, and Figure 8 is obtained by simulating the ISFET model. Is it that way?”
I should note that all the figure abstained by simulation of the validated macro-model, as I said before in section 3 we investigated the temperature effects, so the origine of the figure 7 and 8 is the extracted data from the model.
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Comment 7
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“I think table 3 and table 4 are redundant because the data provided in both table are printed in figure 8 y 9 respectively. Note also that there are discrepancy between them”
Sir Table3 report the coordinate of the isothermal point, and the table 4 report the dependency of the sensor to the temperature.
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Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript "Temperature compensation circuit for ISFET sensor" describes the temperature influence on the ISFET device response to changes in pH. The authors propose a compensation circuit, which should eliminate the impact of temperature on the sensor response to pH. As a main message of the paper, the authors emphasize the importance of such compensation circuit. However, the application, device structure and measurement procedure are not described well enough.
Authors show the need of temperature compensation. However, the origin of such dependence needs to be described as well. An interfering ion is shown in the Figure 1, but not described in the text. Line 90: site binding theory is the correct term instead of "site bond" Line 129: "Kyiv" is correct. In Section 4 authors describe two methods to compensate temperature influence. However, it's not clear which one was used by authors and what is the gate material of REFET? More details on measurement procedure are required. How are the solutions exchanged? A schematics or a photograph of the final device with ReFET would help to understand the experiment. It's not clear from Figure 3a (a photograph of the entire setup). With the proposed circuit, can the effect of temperature affecting MOSFET characteristics and thermodynamic effect be compared and separated?
Author Response
Ms. Ref. No.: jlpea-646455
Title: Temperature compensation circuit for ISFET sensor
Journal of Low Power Electronics and Applications
Dear Reviewer,
Thank you for reviewing my manuscript and for paying much attention to its content. Your comments were so consistent. I would like to inform you that the manuscript was revised according to your suggestions. So, the revised version should be more suitable for the reader. You find the final form in attachment.
Here, some response to your comments. I look forward to receiving your reply.
Best regards,
Ahmed GADDOUR
National School of Engineering of Monastir
Tel.: +216 50 998008
E-mail: [email protected]
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Responses for reviewer #2 |
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Comment 1:
Response: |
“An interfering ion is shown in the Figure 1, but not described in the text”
Thank you sir, I would let you now the I presented prototype of circuit hat it can be use to array system, in the section 4, I wrote in the text that the ISFET and the ReFET present a 2 pixel of array
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Comment 2:
Response: |
“However, it's not clear which one was used by authors and what is the gate material of REFET?”
This work we present a new circuit that work in weak inversion regime but unfortunately the proposed circuit is based on simulation, but in this work we present a new demonstration of how the temperature can be compensated using the ISFET/ ReFET set up. But answer your question about the gate material of the ReFET we can use the polytetrafluoroethylene (PTFE), PTFE has a good insensitivity to pH variation, chemical stability, insulating ability, and dielectric strength.
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Comment 3:
Response: |
“With the proposed circuit, can the effect of temperature affecting MOSFET characteristics and thermodynamic effect be compared and separated?”
No, the Temperature coefficient of MOSFET will be always present and it can be reduced but it can’t be neglected?
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Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Thank you for your revision according the suggestions of referees. I think the changes introduced in the paper have improved it.
After a new reading, I have found some issues that I consider it will be worthy to be attended in order to get a carefully edited contribution. I summarize some of theses suggestions:
1. Figure 4 shows three graphics, for three pH buffers, which represent a set of curves, Ids vs Vgs for three differents Vds values. In my opinion these graphics should be re-edited. First of all, the tags with the name of the curves, should be properly ordered, with the same order in all of them. Secondly, they should use the same symbol to represent the same curve in order to maintain uniformity between graphics, and improve readability. For instant: In pH=3 Ids vs Vgs graphic, a black square symbol is used to represent Vds = 2V curve, however this symbol is used in pH=6,91 Ids vs Vgs graphic to represent Vds = 1V curve. Using different symbols and no ordering in tags, for the same value of Vds, make difficult understand and assess the figure at first sight.
2. In Table 1: I think Channel Length parameter units must be revised, it is supposed to be some kind of length unit. Also Tox units must be expressed nm, instead of nM.
3. In line 162, after period, a capital letter should be used.
4. Figure 6. In my opinion, regression curve for Vt1 vs PH should be provided.
5. In my opinion it is worthy to mention or recall in text how figure 7 and 8 were obtained. From the ISFET macromodel simulations.
6. In Figure 8, after deleting Table 3 in the original paper, the tag that shows the wrong data for Isothermal Point for pH = 8 has not be corrected. As it was showns in old Table 3, It is 0.42mA, instead 0.404mA.
7. In Fig 11, the tag VTReFET overwrites the circuit schematic so it difficults reading.
8. In Line 368, Table 6 is referenced, but now this table has be renumbered.
9. Finally, the references numbered 44, 45 and 46 are incomplete. Journal title o conference name is missing.
Author Response
Dear Reviewer,
Thank you for your comments concerning our manuscript entitled “Temperature compensation circuit for ISFET sensor”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval.
We tried our best to improve the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. We appreciate warm work earnestly, and we hope that the correction will meet with approval. Once again, thank you very much for your comments and suggestions.
Kind regards,
Ahmed GADDOUR
National School of Engineering of Monastir
Tel.: +216 50 998008
E-mail: [email protected]
Reviewer 2 Report
I have no further comments.
Author Response
Dear Reviewer,
Thank you for your comments concerning our manuscript entitled “Temperature compensation circuit for ISFET sensor”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval.
We tried our best to improve the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. We appreciate warm work earnestly, and we hope that the correction will meet with approval. Once again, thank you very much for your comments and suggestions.
Kind regards,
Ahmed GADDOUR
National School of Engineering of Monastir
Tel.: +216 50 998008
E-mail: [email protected]
