SLVSDB5B July 2018 – August 2021 TPS65988
PRODUCTION DATA
When routing the USB2 signals to the TPS65988 BC1.2 detection pins and the ESD protection to the TPS6S300 protection device, it is recommended to reduce the amount of excess trace to all of the pins. This will cause antennae and degrade signal integrity. The USB top/bottom signals are shorted together in this example and the same approach can be used if an external USB mux is used. There are several approaches that can be used to get optimal routing; “tap” the USB2 signals with vias that connect the TPS65988 pins, via up to the layer where the pins are located and continue to route on that layer, or a combination of both.
In this layout example, the D+/D- lines are routed to an internal layer from the connector. They are then via’d up to the pins on the devices. The figure below show the complete USB2 routing on SSTX1RX1, High Speed, and SSTX2RX2 layers.