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TUSB522P

SLLSEV9A – JULY 2016 – REVISED OCTOBER 2016

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Copyright © 2016, Texas Instruments Incorporated

Typical Application (continued)

8.2.1 Design Requirements

For this design example, use the parameters shown in Table 2.

Table 2. Design Parameters

PARAMETERS

VALUE

3.3 V

AC Coupling Capacitor (75nF to 265nF)

100 nF

Host to TUSB522P FR4 Length (Inches)

20

Host to TUSB522P FR4 Trace Width (mils)

4

TUSB522P to Connector FR4 Length (Inches)

6

TUSB522P to Connector FR4 Trace Width (mils)

4

EQ1 (RX1P/RX1N)

9 dB (EQ1 = High)

De-Emphasis 2 (TX2P/TX2N)

-6.2 dB (OS2 = Low, DE2 = High)

EQ2 (RX2P/RX2N)

6 dB (EQ2 = Floating)

De-Emphasis 1 (TX1P/TX1N)

-3.5 dB (OS1 = Low, DE1 = Floating)

Output Swing 1 (OS1)

900 mV (OS1 = Low)

Output Swing 2 (OS2)

900 mV (OS2 = Low)

8.2.2 Detailed Design Procedure

The TUSB522P differential receivers and transmitters have internal BIAS and termination. Due to this, the

TUSB522P must be connected to the USB Host and receptacle through ac-coupling capacitors. In this example,

as depicted in Table 1, 100 nF capacitors are placed on TX2P, TX2N, RX1P, RX1N, TX1P and TX1N. No ac-

coupling capacitors are placed on the RX2P and RX2N pins because it is assumed the device downstream of the

TUSB522P will have ac-coupling capacitors on its transmitter as defined by the USB 3.1 specification.