6 Replies Latest reply on Aug 12, 2020 1:50 AM by WoHa_955446

    About cable length  of FX3S or SD3

    WoHa_955446
      1. Dears.

       

      My customer is taking into account of usage of FX3S or SD3 to design SD Card Reader.

      For my question about the max length of USB3.0, I found https://www.cypress.com/comment/283106.

      Do you have any detail benchmark test report or technical description to figure out the performance of FX3s or SD3 as the leghth of usb 3.0 cable

       

      Thank you

      Wonjin Han.

        • 1. Re: About cable length  of FX3S or SD3
          YashwantK_46

          Hello Wonjin Han,

           

          Can you please let me know what you meant by "the performance of FX3S or SD3"?

           

          Is it the USB 3.0 throughput figures with respect to the length of the cable?

          If not, please elaborate on your requirement.


          Regards,

          Yashwant

          • 2. Re: About cable length  of FX3S or SD3
            WoHa_955446

            Hello Yashwant.

            Thank you for your comment.

             

            Your understanding is correct and i'm waiting for your opinion.

             

            Best regards,

            Wonjin Han.

            • 3. Re: About cable length  of FX3S or SD3
              YashwantK_46

              Hello Wonjin Han,

               

              Can you please let me know why this information is being requested?

               

              From the thread description, I could see the target application is for an SD card reader using SD3 or FX3S.
              Please clarify.

               

              Regards,
              Yashwant

              • 4. Re: About cable length  of FX3S or SD3
                WoHa_955446

                Hello Yashwant.

                Thank you for your turnaround.

                 

                I think SD3 is suitable for this application.
                This application is DVRS(VideoRecorder) in which SD3 is responsible for transimitting recording data from USB host to SD on interia user interface for automotive application.
                It's not clear for me that you cypress has the feature road map for SD3 to get the Automotive Certification.
                However, now my customer gaves me inquiry for recommending a possible solution of "SD to USB" design concept regardless of Auto-Qual and performance report as the length of USB cable with SD3 if you have, esepcially max length for stable speed performance.

                 

                Thanks
                Wonjin Han.

                • 5. Re: About cable length  of FX3S or SD3
                  YashwantK_46

                  Hello Wonjin Han,

                   

                  For A to B type cable, it is 3 m for USB 3.0, and 5 m for USB 2.0.

                  For compliance tests with B connector fixture, it is a requirement to use 3 m cable.

                  For the type-C fixture, the maximum cable length is 1.8 meters when testing.

                   

                  The above cable lengths have been used while testing the cypress USB products (SD3 as well) and that too, with a USB-IF certified cable. If a non-standard cable or a cable with greater length than specified (compared to USB spec), the results may differ as the signal quality is affected.
                  Other than the above-mentioned cable length (which are recommended by the USB spec), SD3 hasn't been tested further, because the test results will be highly subjective to the application.

                   

                  If the customer needs to use higher lengths of cable, it is recommended to either use a Retimer or a Hub in between the device and host to maintain signal integrity.


                  Regards,
                  Yashwant

                  1 of 1 people found this helpful
                  • 6. Re: About cable length  of FX3S or SD3
                    WoHa_955446

                    Hello Yashwant.

                    Thank you for your feedback. It's clear for me to understand the influence by the length of cable.
                    Let's wrap this ticket up.

                    Best regards,
                    Wonjin Han.