Hello team,
I received a question from the customer.
Application note slla014a advises to set the characteristic impedance to 90 to 130 ohms, is it the range in the red box that should be 90 to 130 ohms? Or is the range including the range from the cable to the receiver(BLue)? Also, in the case of the red frame, is it necessary to set the characteristic impedance to 90 to 130 ohms on the transmit and receive sides, respectively?
Regards,
Masa
Hello Adachi-san,
The 100 ohms characteristic impedance is referred to the balanced interconnects (media). This characteristic impedance needs to match your termination resistor, see image below. If not properly matched, then you will see reflections and signal integrity issues.
For the red frame question, the 90 to 130 ohms impedance applies to the balanced interconnect. Most systems only require a 50 ohm impedance but this needs to be checked if your Host Controller and Target Controller allow this.
Regards,
Josh
