HD3SS215: How to interface two HD3SS215 chips

Chandana Tadipaneni

Part Number: HD3SS215
Other Parts Discussed in Thread: TMDS442, TMDS181

Hai,

Can we do 4X2 matrix switcher from two 2X1 switchers by HD3SS215 chip. If it is possible can i have reference schematic or circuit diagram?

Thanks & Regards,

Chandana.

over 6 years ago

0 Brian Zhou over 6 years ago

TI__Guru*** 144615 points

you can use TMDS442 for 4x2 mux

0 Chandana Tadipaneni over 6 years ago in reply to Brian Zhou

Intellectual 440 points

Hai Brain,

I need HDMI 2.0 compatibility chip with 4X2 matrix switching. TMDS442 supports HDMI 1.3 a version

Thanks & Regards,

Chandana

0 Brian Zhou over 6 years ago in reply to Chandana Tadipaneni

TI__Guru*** 144615 points

functional may work with multiple switches, but may hard to pass impedance test.

0 Chandana Tadipaneni over 6 years ago in reply to Brian Zhou

Intellectual 440 points

Hai Brian,

Thanks for the reply, can you provide any reference circuit for implementing the functionality. I need final confirmation that can we do " 4X2 MATRIX SWITCHING" ?

Thanks & Regards,

Chandana.

0 Chandana Tadipaneni over 6 years ago in reply to Chandana Tadipaneni

Intellectual 440 points

Hai Brian,

Can i know is their any update?

Thanks & Regards,
Chandana.

0 David (ASIC) Liu over 6 years ago in reply to Chandana Tadipaneni

TI__Guru**** 176231 points

Chandana

It will look like this using the HD3SS215. But you have to take the loss and Ron of the switch into account. As Brian said, it may work functionally but may fail compliance spec.

Thanks
David

0 Chandana Tadipaneni over 6 years ago in reply to David (ASIC) Liu

Intellectual 440 points

Hai David,

Thanks for the block diagram, Can i know what might be the losses due to this architecture and may know what do you mean by "may fail compliance spec"

Thanks & Regards,

Chandana.

0 David (ASIC) Liu over 6 years ago in reply to Chandana Tadipaneni

TI__Guru**** 176231 points

Chandana

Please refer to Dx differential insertion loss in section 7.6. For RTQ package at 3G, the loss is -2.4dB per HD3SS215, so with three HD3SS215, you will have -7.2dB loss without adding the loss from the PCB trace, the connector, etc.

Please also refer to Ron in the datasheet, each device has nominal 8ohm resistor, with multiple HD3SS215 in the path, it will impact the HDMI impedance compliance test.

Depending on whether this is a AC or DC-coupled HDMI application, you may want to consider adding a HDMI retimer at the output of HD3SS215 to compensate for the insertion loss and impedance impact.

Thanks
David

0 Chandana Tadipaneni over 6 years ago in reply to David (ASIC) Liu

Intellectual 440 points

Hai David,

Thanks for the reply, I got your point. I am using DC-coupled HDMI application, Do i need to add extra circuit for compensating insertion loss and impedance impact? Can i know what is HDMI retimer? Can you please look at the schematic diagram once which i have attached below.8688.hdmi 1x2 rev 1.0_Schematic.pdf

Thanks & Regards,

Chandana.

0 David (ASIC) Liu over 6 years ago in reply to Chandana Tadipaneni

TI__Guru**** 176231 points

Chandana

Schematic looks ok, I would remove the 13x2 Berg pin for signal integrity. You may want to take a look at TMDS181 for compensating the insertion loss and impedance.

Thanks
David

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HD3SS215: How to interface two HD3SS215 chips