TUSB542: Diffential Cross talk

1: should be similar, but I need to check again

2: crosstalk is between two channels, so should be same.

3: 1uf and 10uf close 1.8v supply, 0.1uf and 0.01uf close device pin.

4: all thermal pad should be grounded

Hi Brian-san,

Thank you for your support.

For the #1, I'm looking forward to your confirmation.

For the #4, sorry for my unclear question. The GND pad has six vias with a diameter of 0.1 mm and is connected to the inner layer GND. Is it sufficient from a heat dissipation point of view?

Regards,

Yamaguchi

Hi Brian-san,

I recieved feedback from the customer. Could you please support the following questions?

For the #3, if the bypass capacitor is not enough, what kind of problems can be expected?

For the #4, sorry for my unclear question. The GND pad has six vias with a diameter of 0.1 mm and is connected to the inner layer GND. Is it sufficient from a heat dissipation point of view?

Regards,

Yamaguchi

Yamaguchi-san

1. The 10uF targets low frequency noise filtering while 0.1, 0.01uF target high frequency noise coupling. Without sufficient coupling capacitors, power supply noise at certain frequency level will not be filtered out and has the potential of coupling onto the USB signal. 

2. For GND via, please follow the LAND PATTERN EXAMPLE in the TUSB542 datasheet.

Thanks
David