SN74CB3Q3257: crosstalk between B1 and B2

Hi Jingguo,

Crosstalk usually involves adjacent ON/OFF I/O pins, so pins B1 & B2 would not be exempt from this in the SN74CB3Q3257. This is typically more prevalent in high-speed systems, for which case there are common practices to aid in eliminating this issue. These typically involve maintaining sufficient space between the adjacent signal traces running in parallel and utilizing a minimal trace width in conjunction with the spacing adjustments to prevent the unwanted signal coupling between them. 

If this doesn't satisfy your customer, there may be other techniques for minimizing crosstalk in the application depending on your customer's design, if so feel free to send a detailed layout of your customer's application and I investigate other alternatives.

Lastly, here is a glossary containing an in-detail definition of crosstalk, if your customer would like to learn a little more about how this works with adjacent I/O pins.

http://www.ti.com/lit/an/slla471/slla471.pdf

Hi, Santiago, our customer wants to know the maximum frequency at crosstalk between pins B1 & B2 can be ignored, is it 500MHz? their application frequency is 25MHz. 

Hi Jingguo,

This device doesn't have ratings regarding crosstalk, though I can check with the team on that. Where did you get 500MHz from?

Regards,

Hi Santiago, 500MHz is from its bandwidth.