DS125MB203: Interface forum：When the HDMI signal passes through the DS125MB203 equalizer, the signal quality is reduced, find out why

Arabella Zhang

Part Number: DS125MB203
Other Parts Discussed in Thread: TMDS181, TDP0604, TS3DV642, HD3SS215

The HDMI signal goes through the DS125MB203 equalizer and the signal quality goes down. Don't know where the equalizer is set up to go wrong?
I packed the customer's schematics and some of the waveforms from the test into a file to get you to check them out.

Add:1. The faster the speed, the worse the eye image; the eye image of HDMI 2.0 is significantly worse than HDMI1.4.

2.The HDMI connector is connected to the DS125MB203 via AC (The HDMI connector is connected to the DS125MB203 via AC).

Thank you very much!

Best Regards,

Arabella Zhang

weixinnuo.zip

10 months ago

0 Lucas Wolter 10 months ago

TI__Mastermind 21495 points

Hi Arabella,

DS125MB203 is intended to be used for 10G ethernet, PCIe3.0, and SAS2/SATA3 applications. It is not designed to be used for HDMI applications.

I recommend you use TDP0604 or TMDS181 in combination with HD3SS215 or TS3DV642 instead. These devices are designed to be used with HDMI.

Best,

Lucas

0 Arabella Zhang 9 months ago in reply to Lucas Wolter

TI__Intellectual 1690 points

Customer replies that this is a reference Intel design, may DS125MB203 be used in an HDMI connection?

0 Lucas Wolter 9 months ago in reply to Arabella Zhang

TI__Mastermind 21495 points

Hi Arabella,

Can you share this reference design? I would like to see how DS125MB203 is implemented.

Best,

Lucas

0 Arabella Zhang 9 months ago in reply to Lucas Wolter

TI__Intellectual 1690 points

The accessory is the design circuit for the DS125MB203, please also check is it correct?
Additionally, the DS125MB203 register is set as picture:

Thank you very much!

hdmi_rx.DSN

0 Lucas Wolter 9 months ago in reply to Arabella Zhang

TI__Mastermind 21495 points

Hi Arabella,

Thank you for sharing this schematic and register write sequence.

To clarify, is this the customer's schematic or the reference design itself? Has the customer made any changes to the reference design in their application? Or did they copy the design exactly?

In this register write sequence, I cannot see which values were written to each register because they are stored as variables. Can you share the specific values that are written to each register?

How much insertion loss is on the receiver of each DS125MB203 channel? I'm looking for the total insertion loss which needs to be compensated by the MB203, including PCB, connector, cable, etc.

I am additionally reaching out internally to get more information about this Intel reference design.

Best,

Lucas

0 Lucas Wolter 9 months ago in reply to Lucas Wolter

TI__Mastermind 21495 points

Hi Arabella,

I wanted to follow up. Does the customer still need help improving eye quality? Can you share the name of the customer for my information?

Is the customer following this Intel design?

an952-709310-736110.pdf

Best,

Lucas