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ISO7141CC: A valid replacement for medical application?

Genius 15519 points
Part Number: ISO7141CC
Other Parts Discussed in Thread: ISO7741, , ISO6741, ISO7741-Q1

Hi Experts,

Good day. Client would like to use an alternative part.

They had replaced the ISO7741 isolator chips in their design with ISO7141, due to lack of stock. Since these chips are being used in a medical device, we need to know if these chips have medical grade ratings?

Also, do they use reinforces isolation? And if dielectric and ESD specs are any different from ISO7741?

Thank you for your support.

Regards,
Archie A.

  • Hi Archie,

    Thanks for reaching out.

    ISO7741 offers significantly higher performance over ISO7141CC, if ISO7141CC could meet customer requirement then I wouldn't expect to see any issues in ISO7741 meeting customer requirement. Additionally, ISO7741 also offers reinforced isolation.

    We also have ISO6741which is our latest digital isolator device. If ISO6741 meets customer requirement, we recommend customer to use this device. Thanks.


    Regards,
    Koteshwar Rao

  • Hello Koteshwar,

    Thanks for your detailed response.

    So, do parts ISO7141CC and ISO6741 also offer reinforced isolation?

    Thank you for your confirmation.

    Regards,
    Archie A.

  • Hi Koteshwar,

    Just received response from client.

    Their question was about ISO7141 (but couldn't find/tagged this case this part number without "CC"). As described, their original design was with the ISO7741, but they had to replace it with 7141, due to stock issue. Also, 6741 only comes in the SOIC package which would not work for them.

    Could you help answer the queries again with regards to the 7141?

    - Do these chips have medical grade ratings?
    - Do they use reinforces isolation?
    - Are dielectric and ESD specs any different from ISO7741?

    Thank ahead for your guidance.

    Regards,
    Archie A.

  • Hi Archie,

    Thanks for for the update and for sharing additional information.

    Since customer is looking at ISO7141, I assume the package they need is QSOP-16 (package code - DQB-16). Please note that ISO7141 is an older digital isolator family and this family doesn't offer reinforced isolation like the ISO7741 and ISO6741 according to VDE standard. Please see my inputs to your questions below,

    1. I am not sure what medical grade ratings you are looking for. If customer meant to ask if the device is qualified for IEC 60601-1 then the answer is no. While the ISO7741 does 2 MOPP per CSA 60601-1 and IEC 60601-1 with 250Vrms working voltage for DW-16 package. DBQ-16 doesn't meet this requirement due to lower creepage. Please refer to sections 7.6 and 7.7 of ISO7741 for more details on isolation ratings and certifications. Similarly, refer to sections 8.3.1 and 8.3.1.2 of ISO7141 datasheet for its ratings and certifications.
    2. ISO7741 offers reinforced isolation according to VDE 0884-11 while ISO7141 doesn't.
    3. Yes, ISO7741 will offer double the ESD performance compared to ISO7141.

    The best alternative to ISO7741 in DBQ would be the automotive equivalent of the same device, i.e., ISO7741-Q1 in DBQ (full part number - ISO7741QDBQRQ1). Let me know if there are any further questions, thanks.


    Regards,
    Koteshwar Rao