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THVD1551: Is there any data for common-mode noise test ?

Hung Ching Hsu
Expert 3086 points
Part Number: THVD1551
Other Parts Discussed in Thread: THVD1510

Hi Team

My customer is using THVD1551DGKR with ISO7821FDWWR (digital isolator). 

The customer wants to know if TI did common-mode noise test for THVD1551DGKR, and if yes, is it possible to provide the test method and the test result?

I didn't found any parameter related to noise in the datasheet, but there was a word "noise-immune".

What does that actually mean? Is there any material could explain this term?

BTW, the customer is also asking the common-mode noise test data for ISO7821FDWWR, so i posted another thread on E2E.

I only found CMTI parameter in the ISO7821FDWWR's datasheet, which is 100kV/us, is this value also help us to explain the common-mode noise behavior of THVD1551DGKR?

Thanks. 

  • 0
    TI__Mastermind 25705 points

    Hi,

    What kind of common mode noise test the customer is interested? RS485 transceiver has good common mode noise immunity due to its differential signaling, which is not exactly same as CMTI (transient immunity). You can refer to this app note for the detail.

    www.ti.com/.../slla322.pdf

    What's the application and what's the requirement?

    Regards,

    Hao

  • 0 in reply to Hao L
    TI__Expert 3086 points

    Hi Hao

    I just added application information to "thread tracking toolkit".

    Sorry, I didn't know there are many kinds of common mode noise test. 

    I'll confirm with the customer about the test type and requirement. 

    I understood THVD1551DGKR have good common-node noise immunity because of differential signaling, is there any material to show how great it is?

  • 0 in reply to Hung Ching Hsu
    TI__Mastermind 25705 points

    Hi,

    What I meant to ask is the system requirement on the noise immunity. Otherwise it's hard to quantize the performance.

    I attach a DPI (direct power injection) testing result of THVD1510 for your reference. The test is to check the device's immunity with injected RF common mode power. However the result itself might not mean much. 

    I also copy the bus waveform from one of the data point, showing how the signal looks with the common mode noise.

    Please let me know if you get further questions.

    Regards,

    Hao