SPRS993E March 2017 – December 2018 DRA76P , DRA77P
PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
The SATA data signal traces must be routed to achieve 100 Ω (+/-10%) differential impedance and 60 Ω (+/-10%) single ended impedance. The signal ended impedance is required because differential signals can’t be closely coupled on PCBs and therefore single ended impedance becomes important. 60 Ω is chosen for the single ended impedance to minimize problems caused by too low an impedance.
These impedances are impacted by trace width, trace spacing, distance to reference planes, and dielectric material. Verify with a PCB design tool that the trace geometry for both data signal pairs results in as close to 100 Ω differential and 60 Ω single ended impedance traces as possible. For best accuracy, work with your PCB fabricator to ensure this impedance is met.
Table 7-20 shows the routing specifications for the SATA data signals.
PARAMETER | MIN | TYP | MAX | UNIT |
---|---|---|---|---|
SATA signal trace length (device balls to SATA connector) | 3050(1) | Mils | ||
Differential pair trace skew matching | 5 | Mils | ||
Number of stubs allowed on SATA traces(2) | 0 | stubs | ||
TX/RX pair differential impedance | 90 | 100 | 110 | Ω |
TX/RX single-ended impedance | 54 | 60 | 66 | Ω |
Number of vias on each SATA trace | 0 | Vias | ||
SATA differential pair to any other trace spacing | 2×DS(3) |
Item | Description | Reason |
---|---|---|
ESD part number | None | ESD suppression generally not used on SATA |