https://e2e.ti.com/support/isolation-group/isolation/<p style="display:none;">blank</p>en-USTelligent Community 13https://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1690523/iso3086-external-current-at-visoout/6514705Mon, 19 Oct 2026 15:20:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:63d390ae-48d0-4928-9f83-5450170ce31eJustin LewisHi, Can you please clarify your question? ISO3086 does not have a VISOOUT pin. Perhaps you are referring to the driver/receiver outputs? Also, by &quot;extra&quot; current, do you mean the output current? Best regards, Justinhttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1689006/iso6763-desiging-with-iso6763dwr/6514082Mon, 19 Oct 2026 04:15:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:6ea8055b-fe4b-4b90-b781-587768cdfd96SvHello team, Awaiting your replyhttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1690523/iso3086-external-current-at-visooutMon, 19 Oct 2026 02:48:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:2bef6f2b-0d66-4599-822c-8d962a3588bcuser4090349Part Number: ISO3086 Hello Can I have some extra current at VISOOUT when the primary is powered by 3.3V. I don&#39;t need a lot extra current, 1mA is fine.ISO3086https://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1679862/isow1412-isow1412-radiated-emissions-with-two-devices-used-as-an-rs-485-repeater/6513457Fri, 16 Oct 2026 16:13:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:021898f9-b36d-487a-bfd4-4ed05d4ee1abEric HackettRudolf, We will email you directly and I&#39;ll close this thread for now. Regards, Eric Hacketthttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1679862/isow1412-isow1412-radiated-emissions-with-two-devices-used-as-an-rs-485-repeater/6512855Fri, 16 Oct 2026 06:44:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:e009a534-97a3-482b-8fa2-692487e1d7ccRudolf DichlerYes, please contact me via my email address so that I can respond.https://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1689617/sn6501-sn6501-excessive-inrush-current-during-startup/6512805Fri, 16 Oct 2026 05:51:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:057aade0-e3cb-4f5f-91d5-391d1c83ced4Prateek VermaHi, Yes, this is realistic. The SN6501 does not have internal soft-start or current-limiting features. During startup, the output capacitors act as a short circuit, causing high inrush currents. Mitigation Techniques: Limit Capacitance: Keep output capacitance within the recommended range ~(1uF - 5uF) Use LDO with low short-circuit current limit. Use SN6505: Switch to the SN6505, which includes a built-in soft-start feature to manage this exact issue. Thanks, Prateekhttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1689919/iso1044-iso1044-can-termination-resistance/6512401Thu, 15 Oct 2026 20:14:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:1a0676e9-9b17-4dfe-a4db-b384cc7f8117Eric HackettRain, Thanks for bringing this to E2E. You are correct that CAN nodes at the end of the CAN bus need to be terminated with 120 ohms, and the overall impedance of the CAN bus should be as close to 60 ohms as possible. The reason that 59 ohm resistors were chosen was purely for the availability of that value in a high tolerance resistor. The next value up at that tolerance is 62 ohms, and anything in between is a finer tolerance which comes with higher cost. Again, the overall goal is to keep the CAN bus impedance to as close to 60 ohms as possible. The ISO1044 can technically drive a CAN message with a CAN bus as low as 45 ohms and up to 70 ohms, but the CAN bus driver is optimized for 60 ohms, along with that being the characteristic impedance of typical CAN cabling. Please let us know if you have any other questions. Regards, Eric Hacketthttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1683653/isom8110-ep-optocoupler-selection/6512346Thu, 15 Oct 2026 18:52:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:8d337676-0e4b-483e-868f-8074f4a1dd35Aaditya V.Hi Nishant, Thanks for the questions, there are quite a few questions and it is difficult to read through all of them and provide detailed feedback. Since this thread has bounced around several topics and also has been open for some time, would you be open to call and discuss your questions and review your application? I have sent a friend request over private messages, Please feel free to reach out so I can provide my email so we can setup some time to call and discuss. Regards, Aadityahttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1689855/iso7740-nc-pin-connection/6512338Thu, 15 Oct 2026 18:44:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:2b34a0a9-8e8b-4012-8c08-46dad01f498bAaditya V.Hi Jade, Please refer to this FAQ: [FAQ] Can channel input/output pins on a digital isolator be left floating? [FAQ] Do I connect NC pin to GND, VCC, or leave it floating? Regards, Aadityahttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1683653/isom8110-ep-optocoupler-selection/6512000Thu, 15 Oct 2026 14:04:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:2aa2af8c-aae8-43f3-ab7f-15af9b2a0d04Nishant GuptaAdded points to the earlier questions please reply soon combining all questionshttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1683653/isom8110-ep-optocoupler-selection/6511997Thu, 15 Oct 2026 14:03:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:aa0919cb-b8cd-4587-80f8-f6868bc5ea0bNishant GuptaHello TI Team, I would appreciate your guidance on the following points to finalize the circuit design and proceed with testing. Optocoupler-based switching: My bias current is approximately 50–70 &#181;A. If I use a phototransistor-output optocoupler, will its output transistor be sufficient to switch the external BJT, or will an additional transistor be required? Please clarify how the optocoupler&#39;s VCC and collector pull-up resistor should be connected to bias the external BJT, considering that a 5 V supply is already available in my application internal pull up resistor with open colector configuration my BJT running as switch. Base-current requirements: The external BJT operates in an open-collector configuration, and its required base current is relatively low. How can I ensure reliable switching in both configurations—with and without the additional external transistor? ISO7421-EP current capability: My FPGA can provide approximately 25 mA at its output. Can the ISO7421-EP reliably interface with this signal? Please clarify its output-current limitations and the appropriate interface requirements. Isolation failure analysis: The ISO7421-EP uses capacitive isolation. Although there is no direct conductive connection across the isolation barrier during normal operation, what could happen if the barrier degrades or fails? Could leakage or an isolation breakdown cause the input and output grounds to become electrically connected and affect the overall system? Switch failure modes: Under normal operation and potential isolation failures, could the external switching circuit become permanently ON or permanently OFF? What failure mechanisms should I consider, and what precautions would you recommend ensuring a predictable, fail-safe state? Please provide clear technical guidance and relevant datasheet references so that I can finalize the circuit and plan the necessary validation tests. Thank you for your support. Best regardshttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1689919/iso1044-iso1044-can-termination-resistanceThu, 15 Oct 2026 10:11:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:ad55ea1f-aaa8-4c1d-9c18-28703a95cca7Rain WangPart Number: ISO1044 What RTERM resistor value does your company recommend for CAN Termination? The datasheet states that termination may be a single 120ohm resistor. From the following public board design, the terminal resistor used by TI is 59 ohms, which is less than the 60 ohms specified in the datasheet. Could you please share the reason for selecting a 59-ohm terminal resistor? ISO1044DEVM Evaluation board | TI.comISO1044AppliancesISO1044DEVMhttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1689855/iso7740-nc-pin-connectionThu, 15 Oct 2026 08:30:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:fbcd9a34-06d6-4dc2-b9a4-6d1aca635e20Jade HanPart Number: ISO7740 Hello team, My customer is drawing circuit with our ISO7740 for their cobot pjt, and was wondering how to connect the NC pins. It was not quite clear on the datasheet, could you please share your feedback on below? IC&#39;s NC pin: Should leave floating or connect to GND? Unused pin: Should leave floating or connect to GND? Thank you.ISO7740Roboticshttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1687079/iso7740-spi-with-digital-isolator/6511422Thu, 15 Oct 2026 04:00:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:5304dab1-efa0-4a21-87f5-eec7094682f9Aaditya V.Hi Ahmed, I still am not completely sure what you mean in regards the points you have mentioned. I will try my best to explain. From my understanding, the Dout signals are all going in one direction, same as the clock signal. As you mentioned an isolator with 3 forward and 1 reverse can be used to accommodate the clock signal. The clock signal from the ADC itself can be split to each isolator. This would be before the isolator. I believe you have the correct understanding as far as the orientation of the clock signal, I would recommend splitting the clock signal to each isolator at the source of the clock signal itself. Regards, Aadityahttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1688430/isow3086-when-will-production-parts-be-available-and-at-what-price/6510626Wed, 14 Oct 2026 14:30:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:983c7931-7632-42ae-830b-945fa1bd5659Justin LewisHi Dennis, I am not sure why my message was sent to your personal, and from a noreply address, however I will reach out to you via your work email. Best regards, Justinhttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1689617/sn6501-sn6501-excessive-inrush-current-during-startupWed, 14 Oct 2026 14:09:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:1f3baea5-ec10-4a77-89fa-db2d00996634İsmet ŞenPart Number: SN6501 Hello TI Support Team, I am running a SPICE simulation using the SN6501 based on the typical application circuit from the datasheet, where the output is regulated with an LDO. During startup, when the output capacitors charge up, I am observing inrush currents from the source reaching up to 1.5A. Could you please clarify whether this high inrush current a realistic behavior for the SN6501 in actual hardware? If this is a real behavior, what are the recommended mitigation techniques for this inrush current? Thank you for your support. Best regards,SN6501https://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1687079/iso7740-spi-with-digital-isolator/6510082Wed, 14 Oct 2026 06:06:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:75969be2-78dd-448f-ab9d-1c60ed0b508fAhmed MostafaHi Aaditya, Yes, you&#39;re right, I just give you an example. Of course, I will choose another digital isolator that has 3 forward channels and 1 reverse channel for that case. But I discuss with you the two cases above: 1- Connecting two clocks together after isolator. 2- Use only one of them. Best Regards, Ahmed Mostafahttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1687079/iso7740-spi-with-digital-isolator/6510045Wed, 14 Oct 2026 05:40:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:43b93f8d-7c2b-48be-a900-93f009c8e416Aaditya V.Hi Ahmed, Looking at both schematics, it seems that you are crossing the clock signals into different ground planes. This essentially makes the clock signal bypass the isolation barrier and can cause additional issues. Can you please confirm the ground plane of the ADC? Using the top isolator for reference, i would like to understand if the ADC ground reference is on the right side of the isolator or the left side of the isolator. Regards, Aadityahttps://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1689006/iso6763-desiging-with-iso6763dwr/6509954Wed, 14 Oct 2026 03:52:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:7ae3fad8-91f4-4dd5-a5e7-29e6ea40af8dAaditya V.Hello, Thanks for reaching out. please give me additional time to respond.https://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1683653/isom8110-ep-optocoupler-selection/6509675Tue, 13 Oct 2026 21:09:00 GMTcb01d8b2-d089-468d-babb-77d1d8683490:02f22e5b-20ae-47a0-9502-78332163a8d7Eric HackettNishant, Thanks for your patience, we&#39;ll get back to you by end of business tomorrow. Regards, Eric Hackett