TUSB551

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SLLSEJ1A – MARCH 2014 – REVISED MARCH 2014

9 Applications and Implementation

9.1 Application Information

One example of the TUSB551 used in a Host application on transmit and receive channels is shown below. The

re-driver is needed on the transmit path to pass transmitter compliance due to loss between the Host and

connector. The re-driver uses it’s equalization to recover the insertion loss and re-drive the signal with boosted

swing down the remaining channel, through the USB3.0 cable, and into the device PCB. Additionally, the

TUSB551 is needed on the receive channel for the Host to pass receiver jitter tolerance. The re-driver recovers

the loss from the Device PCB, connector, and USB 3.0 cable and re-drives the signal going into the Host

receiver. The equalization, output swing, and de-emphasis settings are dependent upon the type of USB3.0

signal path and end application.

Figure 11. Application for Host Systems

9.2 Typical Application

9.2.1 Transmit and Receive Channels

The TUSB551 is placed in the transmitter channel and connected to a USB3 Type-A connector. This particular

example shows the polarity swapped on the RXP/N and TXP/N differential pairs. The positive signal may be

routed to RXN as long as the corresponding output, TXN, is routed to the positive terminal on the connector

(SSTXP). This allows routing to be done without crossing the differential pair signals and using extra vias. The

EQ and DE terminals must be pulled up, pulled down, or left floating depending on the amount of equalization or

de-emphasis that is desired. The OS terminal must be pulled down or left floating depending on the required

output swing. In this example, the EQ terminal is pulled low through a resistor and the OS and DE terminals are

left floating.

Figure 12. Transmitter Channel Implementation with Differential Pair Polarity Swapped

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