Hi,
Customer is considering DS99R105/106 by using USB3.0 cable.In this case, should the output differential termination resistance(Rt) be changed 90Ω ?
Could they use USB3.0 cable ? Is there sufficient results for that ?
Best Regards,
Kato
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Hello Nasser -san, T.K, Chin -san,
Thank you for the reply. I understood that it is possible to change the external termination from 100 ohm to 90 ohm. So, do you have the information what the cable and connector impedance are acceptable for signal integrity ? DS99R105 and DS99R106 have the signal integrity margin for USB3.0 cable and connector ?
In addition, regarding AC coupling connection, 100nF between the serializer and deserializer, what value is acceptable for production tolerance ?
Best Regards,
Kato
Kato-San,
DS99R105/6 have been characterized with 100 Ohm impedance in mind. The customer can try 90 ohm termination and check the signal integrity.
AC coupling Capacitor value is a function of the data pattern they are planning to use. For 8/10 bit coded data 100nF is fine. On the other hand, if they have data pattern with high low frequency content then at least 4.7uF capacitor is the recommended value.
Regards,,nasser