Part Number: TUSB501
Other Parts Discussed in Thread: TUSB551,
Hi Support team
I have a customer question on using TUSB501 to replace NXP PTN36221A:
I would like to inquire you about TUSB501 for the new project we are working on. It is a 3.3V USB 3.0 single channel redriver. In our scheme, the data is proprietary, not USB 3.0. It would be the receiver channel redriver for FPGA, after receiving 960Mbps data over long cables. The logic is CML and it is AC coupled. In addition, we need insert capacitor on this link for galvanic isolation.
Currently we used NXP PTN36221A in other project for the same purpose, but the unpleasant thing is its 1.8V supply, while this design has very limited power budget, thus we were thinking of using 3.3V redriver that shares the rails with rest of circuit, and we don’t have to make switching regulator for 1.8V. So we found TUSB5.0 from TI. It seems like a good fit except that its datasheet is too short and doesn’t cover as much details as its 1.8V TUSB551 counterpart.
Below are my questions so far. .
1) Can we assume the difference between TUSB501 and TUSB551 is supply voltage? That way we could refer to TUSB551’s datasheet which is much more detailed and application oriented.
2) Could you advise the impact if we have AC coupling on both TUSB501’s Tx and Rx sides? We only need it for receiver channel.
a. For its Rx, I understand USB 3.0 link is AC coupled by nature, thus there shouldn’t be a problem using TUSB501 for AC coupled CML input.
b. For its Tx, we are planning to insert 150pF 3KV cap for isolation purpose. I don’t know whether it would affect its normal operation (e.g. receiver detection), as well as output swing setting because of the 150pF.
As I understand the device, we AC couple with 0.1 uf caps on the output of the TUSB501, can we AC couple again on the input to the device, and if so, I believe it would need to be a larger value than the 0.1uf.
Can you comment on the above?
Thanks
Jeff
