Other Parts Discussed in Thread: TUSB9261
Hello,
We are designing USB to SATA conversion system using TUSB1142 and TUSB9261.
To create PCB layout, we are facing some concerns as below.
1) When refer page 41, Figure 9-1. Typical USB Host Application and page42, Table 10-1. Design Parameters on TUSB1142 datasheet.
There is requirement that "2 inches <= XAB <= 12 inches - XCD"
What is the reason of minimum length 2 inches? In general thinking shorter length is better.
2) CAC-USB1 and CAC-USB2 are placed Figure 9-1. Typical USB Host Application but no recomendation of chip size.
Can we use 0603 size capacitors?
Because 0402 size is requested on TUSB9261 application note. How about TUSB1142 case?
3) 10.1.2 SuperSpeed Differential Routing on TUSB9261 datasheet is described, Maximum trace length mismatch between SuperSpeed USB signal pairs should be no greater than 2.5 mils.
And the spacing between the TX and RX signal pairs for each interface be five times the width of the trace.
However TUSB1142 requirements are 5mils mismatch and three times spacing.
Is it better to apply 2.5mils mismatch and five times spacing rule for both devices?
Regards,
Mochizuki
