TPD12S521: HDMI broken which differential lines shorted to ground but ESD IC still good.

Martin Wen

Part Number: TPD12S521

Hi Bros,

My customer is using our HDMI ESD. Recently, they found 20 in 500 products' HDMI port broken in field application. During testing, the differential lines shorted to ground, but strange is that our ESD IC still good. Seems ESD protection IC doesn't protect our HDMI? Below is the sch. Do you have any suggestions for the reason or sch comments?

over 6 years ago

0 Thomas Amlee over 6 years ago

TI__Genius 9230 points

Hi Martin,

I will take a closer look into this issue, shortly.

Thanks,
Thomas A.

0 Thomas Amlee over 6 years ago in reply to Thomas Amlee

TI__Genius 9230 points

Hi Martin,

The schematic looks good, but why did the they short the differential signals to ground?

The protection diodes conduct at (+/-) 9V, so shorting a differential signal to ground would not conduct the ESD diodes, but would likely damage the HDMI transmitter.

Thanks,
Tom A.

0 Martin Wen over 6 years ago in reply to Thomas Amlee

TI__Prodigy 615 points

Hi Tom

Thanks for your reply. When good the differential lines didn't shorted to ground. But shorted to ground after HDMI broken. Seems ESD IC didn't protect the HDMI port.

0 Thomas Amlee over 6 years ago in reply to Martin Wen

TI__Genius 9230 points

Hi Martin,

This part does not protect against short to ground. It protects against ESD events. I would look into undervoltage protection products if more interested in short to ground.

Do you have more information about how the ports broke & the current state of the differential signals after breaking?

- Tom

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TPD12S521: HDMI broken which differential lines shorted to ground but ESD IC still good.