TUSB546A-DCI: Used as DP redriver purpose only

Antony

Why not use DP159?

Thanks
David

HI David,

DP159 converts DP++ to HDMI, but the customer needs this solution to be located at the output of graphics card and being able to  support all 3 cases   I think it should be a "DP redriver" instead of "DP++ to HDMI redriver"??

Antony

Antony

If the graphic card supports both DP and HDMI, then I would think this is a DP ++ and DP159 is the right solution. Please check with the customer on the output of the graphic card.

If the output of the graphic card is DP only, then you need an active DP to HDMI protocol converter, which unfortunately TI does not have a solution.

Thanks
David

Hi David,

Among these 3 cases, GPU is configurable to comply all of them which means there's only one set of HW design (including the redriver and DP connector) which need to support these 3 cases.

• Case1: GPU output is DP signal, and they need a DP redriver between GPU and DP connector so that a DP monitor can be connected to the DP connector.
• Case2: It looks to me that the GPU output a signal which is AC-coupled signal with HDMI protocol. THey need a redriver between GPU and DP cpnnector, and the "adapter passive" would translate the signal to a normal TMDS HDMI signal for HDMI monitor. (Please see details in  https://www.delock.de/infothek/DisplayPort/displayport_e.html )
• Case3:GPU output is DP signal, and they need a DP redriver between GPU and DP connector so that a DP monitor can be connected to the DP connector  The "Adapter active" would translate the DP signal (from DP connector) to HDMI signal so that HDMI monitor can be connected to "Adapter active"

It's clear that DP redriver should be used in case1 and case3, but we're not sure if the same DP redriver is workable for case2 or not?  Have you heard of such special AC-coupled signal with HDMI protocol?  Can we use DP redriver to support it?  How?

Thanks!

Antony

Antony

For Case 1 and 2, I think this is the solution you are looking for.

Case 1 uses TDP142, and Case 2 uses DP159 (Retimer) or DP158 (Redriver). 

Thanks

David

Hi David,

Can you help me to take a look at the words as below quoted from "https://www.delock.de/infothek/DisplayPort/displayport_e.html"  I think it's talked about the case2 with "adapter passive" conencted.  Based on the description as below, what is the signal type at the output of graphics card?  Do you think it's a general DP++ signal?  If so, why it's mentioned as "HDMI protocol"?  It also mentioned the passive adapter would do the level shifting, does it imply the output of graphic card (which means the input of the passive adapter) is a general DP++?  Thanks!

But if for example an adapter to HDMI is connected, the graphics card is instructed to use the HDMI protocol. Then the downstream passive adapter (so called impedance transformer / level shifter) adjusts the different signal levels and impedances LVDS or TMDS always congruent with the target interface. However, the support of DP++ and an appropriate labeling on devices is optional and depends on the manufacturers.

Antony

Antony

From the description, it sounds like the GPU output is a DP++ output.

Thanks
David

Hi David,

If it's DP++ output, why does it be labeled as "HDMI protocol"?  What is your comment?

Thanks!

Antony

Antony

Devices which implement dual-mode will detect that a DVI or HDMI adapter is attached, and send DVI/HDMI TMDS signals instead of DisplayPort signals.

Thanks

David

Hi David,

So, if this dual-mode capable GPU detect DVI/HDMI (passive) adapter attached to this DP connector, what kind of redriver (which TI part number?) can be used here?

Antony

Antony

Between GPU and DP connector, TDP142 is the solution.

For the passive adapter, DP159 is the solution.

Thanks

David

Hi David,

So, if a laptop with dual mode GPU want to support all the three application scenario (as below) at one single DP connector, there's not a single redriver IC solution can support them all between GPU and the DP connector, right?

1. DP output
2. active adapter (like https://www.amazon.com/Cable-Matters-DisplayPort-Supporting-Technology/dp/B00EDT0072/ref=sr_1_3?hvadid=77996676032161&hvbmt=be&hvdev=c&hvqmt=e&keywords=dp+active+adapter&qid=1559876282&s=gateway&sr=8-3 ) 
3. passive adapter (like https://www.amazon.com/Plugable-DisplayPort-Supports-displays-3840x2160/dp/B01GW8DZV4/ref=sr_1_2?keywords=passive+displayport+to+hdmi&qid=1559875536&s=gateway&sr=8-2

Antony

Hi David,

But, the competitor replied to customer that they can use the solution listed below to support all three cases at one DP connector from the dual mode GPU.  THese solution looks to me like a pure DP redriver.  What is your comments for the comments from the competitors?

• ps8461
• PI3DPX1203B

Antony

Antony

Please take a look at the block diagram I drew in my previous reply, it is the same solution.

Thanks

David