value of VSADJ resistor for the TMDS141

Michael Rivlin

Other Parts Discussed in Thread: TMDS141

Per Data Sheet (p.6) of the TMDS141, resistor for TMDS compliant voltage swing range ("VSADJ resistor") is recommended to be between 4.6k and 4.68k. Can we use resistor of higher value than 4.68k in specific applications (reducing output strength for passing EMI test, for example)?

Any help will be much appreciated.

over 12 years ago

0 Elias Villegas M. over 12 years ago

TI__Guru* 76130 points

Hello,

Increasing the VSADJ resistor will indeed cause the voltage swing to be lower and so the EMI will be reduced.

I don't know what compliance testing you are making, if you want the TMDS141 to be compliant with the HDMI 1.3a Spec, you have to follow the datasheet.

Regards.

0 Michael Rivlin over 12 years ago in reply to Elias Villegas M.

Prodigy 225 points

Hello Elias,

And what about application when TMDS141 is used as intermediate stage and followed by an on-board HDMI circuit?

Best Regards

0 Elias Villegas M. over 12 years ago in reply to Michael Rivlin

TI__Guru* 76130 points

Hello,

The answer is yes, you can adjust the VADJS to reduce the voltage swing, I'm just saying that going beyond the spec limits may cause the device to not meet the compliance requirements.

Regards.

0 Michael Rivlin over 12 years ago in reply to Elias Villegas M.

Prodigy 225 points

Hello Elias,

Thank you for answer. My additional quest. is whether or not this resistor affects other THDS141 parameters (jitter, impedance, etc) if it out of defined in Data Sheet range.

Best Regards

0 Elias Villegas M. over 12 years ago in reply to Michael Rivlin

TI__Guru* 76130 points

Hello,

The answer is no, only the amplitude.

Regards.

0 Michael Rivlin over 12 years ago in reply to Elias Villegas M.

Prodigy 225 points

thank you very much Elias!

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value of VSADJ resistor for the TMDS141