TUSB522P: How to set EQ/DE/OS to improve USB 3.0 compliance test.

Nelson Chang

Part Number: TUSB522P

Tool/software:

We are using the TUSB522P between the Host and the connector. During the USB 3.0 compliance testing, several tests failed.

Please refer to the attached document for details. Total Jitter fail.

USB3_CC1.pdf

Currently, our EQ/DE/OS settings are as shown in the schematic. Do you have any suggestions on how to modify these settings to improve the test results?

PIN	DESCRIPTION	LOGIC STATE	TYP	UNITS	DUT configuration 1	DUT configuration 2
EQ1/EQ2	Receiver equalization amount	Low	3	dB
		Floating	6	dB
		High	9	dB	V	V
OS1/OS2	Transmit output swing amplitude for the transition bit	Low	0.9	Vpp
OS1/OS2	Transmit output swing amplitude for the transition bit	High	1.1	Vpp	V	V
DE1/DE2	Transmit de-emphasis amount	Low	0	dB
		Floating	-3.5	dB
		High	-6.2	dB	V	V

Thank you

Nelson

8 months ago

0 Nicholaus_Malone 8 months ago

TI__Mastermind 27925 points

Hi Nelson,

The TUSB522P can improve system jitter if the jitter source is related to ISI. It doesn't correct for other sources of jitter.

ISI jitter is deterministic jitter, and the compliance results show passing deterministic jitter.

It seems like there may be other sources of jitter in the system causing the issue, but the DE setting should affect your Tx compliance results the most. Change these values, re-run the test and see if there is an improvement. If not, then you may need to confirm that the input jitter into the TUSB522P is passing compliance.

Regards,

Nicholaus

0 Nicholaus_Malone 8 months ago in reply to Nicholaus_Malone

TI__Mastermind 27925 points

Hi Nelson,

Is there an update on this issue?

Regards,

Nicholaus

0 Nelson Chang 7 months ago in reply to Nicholaus_Malone

Prodigy 130 points

Hi Nicholaus,
Following your advice, I made adjustments to the DE, and the results meet the test requirements. Thank you for your assistance!”

Regards,
Nelson

0 Nicholaus_Malone 7 months ago in reply to Nelson Chang

TI__Mastermind 27925 points

Glad to hear it! I’ll mark as resolved then.

Thanks,

Nicholaus

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TUSB522P: How to set EQ/DE/OS to improve USB 3.0 compliance test.