TPS2549-Q1: TPS2549-Q1 D+/D- has signal after PD plug out

zhimin xia

Part Number: TPS2549-Q1
Other Parts Discussed in Thread: TPS2549, TUSB212

Dear TI friend,

I find there are signals in TPS2549-Q1 D+/D- when I plug out the USB device, and Vbus out also has a discharge. the waveform as below, I test with mobile phone and U-disk, it is almost same.

can you advice it is in normal for TPS2549-Q1 and what is the reason? because it seems strange.--Thank youTPS2549 signal in PD plug out.docx

over 6 years ago

0 Bob Ma over 6 years ago

TI__Expert 8980 points

Hi, Zhimin,

I think TPS2549-Q1 is configured at CDP or SDP mode in your case. If TPS2549-Q1 is configured at CDP or SDP mode, the internal analog switch will be turned on and TPS2549-Q1 will not apply any signals on D+/D- except for primary and secondary detection. So the signals in the waveform is from other devices.

What other devices are connected to D+/D- after PD plug out? What's your setup? Can you provide zoom in waveform of VBUS discharge? I want to see the VBUS discharge time and see what triggered VBUS discharge.

Regards,
Bob

0 Bob Ma over 6 years ago in reply to Bob Ma

TI__Expert 8980 points

Hi, Zhimin,

Have you get you issue resolved? If no more reply, I will close this thread.
Feel free to ask any questions.

Regards,
Bob

0 zhimin xia over 6 years ago in reply to Bob Ma

Prodigy 230 points

the problem is still in checking. maybe will have a testing result in next monday.

0 Bob Ma over 6 years ago in reply to zhimin xia

TI__Expert 8980 points

Hi, Zhimin,

I am sure that the abnormal waveform is not come from TPS2549-Q1, you can bypass this part to debug. I will leave for Chinese new year next week, hope you can get it fixed.

Happy new year!

Regards,
Bob

0 zhimin xia over 6 years ago in reply to Bob Ma

Prodigy 230 points

Dear Bob

after check, the signal is created by TUSB212, no related with TPS2549, Thank you for your support.

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TPS2549-Q1: TPS2549-Q1 D+/D- has signal after PD plug out