TMDS261B: TMDS261B about the heat question

Hi Moises,

I have sent the e-mail to you. Please check your e-mail.

  The TMDS261B device is 68 degree C when it is heat serious.  VCC is 3.3V. There are 10 boards that exist this phenomenon.

 The HPD_SINK pin is always the high level when it is used as the input source. Is this situation correct?

 The customer would like to get the reference schematic. Do we have the reference schematic for TMDS261B?

Hi Mickey,

I have sent the available schematic by email.

Remember HPD outputs are 3.3V, you’ll need a level shifter to have 5V in the HDMI connector.

HPD_SNK should be controlled by the HDMI receiver.

How are you controlling S1 and S2?

SCL/SDA need 47k pull-ups to 5V

Could you measure the current consumption with different S1/S2 combinations?

Could you measure the current when there is nothing connected to the TMDS261B?

Regards

Hi Mikey,

The current numbers look fine.

This current consumption is the same for non-heating devices?

The current number are similar to the ones in DS page 10?

What is the rate of heating devices?

When the TMDS261B is not connected to source either sink.

Does it heat too?

What is the current?

Could you try removing the ESD protection on TMDs sink?

Regards

Hi Moises,

Update:
1. When the input signals are not connected to TMDS261B, the TMDS261B current is about 10mA. The TMDS261B device is fine and the heat is not seriously.
2. When the output signal is not connected to TMDS261B, the TMDS261B current is about 10mA. The TMDS261B device is fine and the heat is not seriously.
3. When the customer removes the ESD protection on TMDs sink, the TMDS261B device is still heat seriously.
4. When the HDMI source is connected to TMDS261B and the output port of TMDS261B is connected to the monitor, the TMDS261B device
begins to heat slowly. The TMDS261B current is about 170mA.

Handled by email