TUSB8043A: High Speed Serpentine/Sawtooth Length Matching

Michael Hwang

Part Number: TUSB8043A

Hi,

In App Note SLLA414(August 2018), the recommendation is like this, namely that the length and spacing of the sawtooth should be larger than 3W and 2A, respectively.

However, other sources are recommending differently:

NXP recommends the spacing to be LESS:

Altium and Toradex recommends both the width and spacing should be less:

Which is correct?

over 2 years ago

0 Malik Barton57 over 2 years ago

TI__Guru 64326 points

Hi,

I am looking into this and will get back to you as soon as possible.

0 Malik Barton57 over 2 years ago in reply to Malik Barton57

TI__Guru 64326 points

Hi,

I agree that the the separation of the serpentine pattern here should be less than double the spacing between the straight trace. I will look into getting this corrected in theSLL414 document.

0 Michael Hwang over 2 years ago in reply to Malik Barton57

Prodigy 30 points

Thanks. What about the length of the serpentine pattern? I can see an argument both ways, if it's too long then it becomes uncoupled, if it's too short then the signal can couple to the other side of the serpentine pattern.

0 Malik Barton57 over 2 years ago in reply to Michael Hwang

TI__Guru 64326 points

I would say the length of the serpentine pattern should be long (equal to or slightly greater than three times the width of the trace) to avoid crosstalk between the "edges" of the pattern.

Interface

Interface forum

TUSB8043A: High Speed Serpentine/Sawtooth Length Matching