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sasi , 01-08-2025, 01:20 PM

Hi, I have designed a 16-bay 2.5-inch SATA backplane on easyeda pro, want to make trace for 12 Gbps, so, what is the trace width, trace spacing and FR material? pls guide me

Shashi , 01-08-2025, 01:32 PM

@Robert Feranec @Phil

Robert Feranec , 01-08-2025, 01:39 PM

this may help: https://youtu.be/Lqc1jmbSxnE

Robert Feranec , 01-08-2025, 01:44 PM

especially watch the point 2 - based on stackup and required impedance you need to calculate the track geometry. You can also use calculator such Saturn PCB toolkit - it is a free software https://saturnpcb.com/saturn-pcb-toolkit/

Robert Feranec , 01-08-2025, 01:48 PM

Also, for higher speed (above 2.5GHz) you may need to be more careful. I made some videos on these topics, for example try to watch this: https://youtu.be/xNGNwO2R2lg

Shashi , 01-08-2025, 01:59 PM

Thanks @Robert Feranec😇 I am using all the rule, from reference from your Video only
4 layer , 3313 Stackup,
L1 and L4 for signal and Power,
L2 and L3 for GND plane
6 mil trace width,
so, my doubt is, what is space between (+) and (-) in differential pair?
and can this able to carry 10 to 12 Gbps dada speed, in SATA backplane?
Thanks

QDrives , 01-08-2025, 10:43 PM

So is L2 for signal and power or for Gnd? What about L4?
3313 is a glass weave style. Do you mean 1x3313 prepreg between L1 and L2?
Isola has a stack-up calculator for impedance that, just like Altium, allows for mixing Dk.

Shashi , 01-09-2025, 02:39 AM

@QDrives sry, there is typo error
L1 and L4 for signal and Power,
L2 and L3 for GND plane

Robert Feranec , 01-09-2025, 06:12 AM

the jlcpcb calculator will give you also the space: https://www.youtube.com/watch?v=owdtLw_EZdU&t=4916s

Shashi , 01-11-2025, 02:10 PM

I am going with 4.6 mil trace witch and 7mil trace space in differential pair impedance 100 Ohm. is their any more for achieving 12 Gbps speed on Slim SAS? what should be better for Routing Corner in my case Line or curve? @Robert Feranec

QDrives , 01-11-2025, 05:13 PM

12Gbps, but what frequency? Or in other words, how many lanes?

Robert Feranec , 01-12-2025, 12:54 PM

I would by probably worried mostly about the length

Shashi , 01-12-2025, 04:31 PM

@Robert Feranec The maximum length of trace 2500 mil. and @QDrives it used for 2.5 inch SAS to slim SAS (SFF 8654 4i) Female PCB mount.

QDrives , 01-12-2025, 08:14 PM

2 lanes, so 6Ghz. I would also look at the loss tangent.