TDP158: No Output when don't connect HPD_SNK

Vincent Li00

Intellectual 2035 points

Part Number: TDP158

Hi Guys

our customer is using TDP158 for HDMI redriver. But we found that:

when we don't connect the HPD_SNK, the HDMI will don't have any output, but when take the HPD_SNK to connect to HDMI socket. It will get the output. could you explain how the HPD_SNK work here? I think the capture should explain it. how to understand the work theory.

Any feedback are appreciated. This issue is very urgent.

thanks

-Vincent

over 7 years ago

0 JMMN over 7 years ago

TI__Guru 60870 points

Hi Vincent,

That is the correct operation. HPD-SINK is high when a powered sink is attached to the redriver, it will not output signals unless this signal is high - see Table 28 in the datasheet.

Regards,

JMMN

0 Vincent Li00 over 7 years ago in reply to JMMN

TI__Intellectual 2035 points

when SINK is attached to the redriver, I think it should be the third red line, right? but the first red line and second one are also normal operation. how to explain the two conditions?

thanks

-Vincent

0 JMMN over 7 years ago in reply to Vincent Li00

TI__Guru 60870 points

HPD_SNK is ignored if Reg09{2} is set via I2C, see the third column. Are you setting this bit?

Regards,
JMMN

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TDP158: No Output when don't connect HPD_SNK