ZHCSKE8D March 2016 – October 2019 DS250DF410
PRODUCTION DATA.
For this design example, the following guidelines outlined in Table 13 and Table 14 apply.
DESIGN PARAMETER | REQUIREMENT |
---|---|
Device placement | Place the DS250DF410 on the receive side of the paddle card such that it is receiving data from the cable, and transmitting towards the host. |
AC coupling capacitors | 100 nF AC coupling capacitors are required for the RX inputs and the TX outputs. |
Cable insertion loss | The raw cable insertion loss including the insertion loss of the paddle card should be ≤ 27 dB at 25.78125 Gbps Nyquist frequency (12.9 GHz). This is to ensure that the total loss at the input to the DS250DF410 is ≤ 35 dB at 12.9 GHz. Assuming a worst-case host-side PCB loss of 7 dB, plus a connector loss of 1 dB, the remaining loss allocated for the raw cable and paddle cards is 27 dB. |
DESIGN PARAMETER | REQUIREMENT |
---|---|
Device placement | A full-active QSFP cable will utilize two pieces of DS250DF410 per paddle card. Typically, one device will be placed on each side of the paddle card. |
AC coupling capacitors | Transmit-side Retimer: 100 nF AC coupling capacitors are required for the RX inputs and are not required for the TX outputs. This link segment will be AC coupled on the paddle card at the opposite end of the cable.
Receive-side Retimer: 100 nF AC coupling capacitors are required for the RX inputs and the TX outputs. |
Cable insertion loss | The raw cable insertion loss including the insertion loss of the paddle card should be ≤ 35 dB at 25.78125 Gbps Nyquist frequency (12.9 GHz). |