HDMI to LVDS Conversion Options

Hello Ajinder Singh,

I am interested in this solution you may have. Could you please specify which ic's are used and if there is some sort of application note that covers such a converter?

Thank you

Murillo,

I am the business development manager for this product area.  We currently do not have anything that will support an HDMI(TM) to LVDS link but I am not sure this is needed.  HDMI(TM) contains audio but LVDS does not.  Do you really need a TMDS(TM) to LVDS translator, DVI --> LVDS?  We could provide a two chip solution for this application if audio is not involved.  The TFP401A or TFP403 DVI recievers hooked up to the SN75LVDS83B FlatLink(TM) transmitter might work depending on the application.  We need to understand what the pixel clock need is for us to determine that we have a potential solution.  Fill free to contact me at r-hubbard2@ti.com.

Regards,

Richard Hubbard

Hi Richard,

We have an application where we need to convert the HDMI to LVDS (video only no audio). Can I use TFP401A or TFP403 and SN75LVDS83B as the  HDMI to LVDS receiver. Is there better solution from TI for single port HDMI.

Thanks n regards

MRK

MRK,

This is our best solution for this application.  We need to understand the pixel clock, bits per color, and refresh rate in order to determine whether this solution has the bandwidth needed.  Once these are known we can have you discuss this with an applicaiton engineer for support.

Regards,

Richard Hubbard

Richard Hubbard,

Wow, glad I ran across these boards, I'm looking to work on a CE class project and decided to do something I wanted to do for myself while I'm at it.  Scouring the net finding no useful information until these posts.  I'm looking for a solution of what you've stated just before... I want to take DVI(from external graphics card) input and convert to LVDS(LCD laptop screen).  Basically I want to take my Lenovo W510 notebook, attach an external desktop graphics card via PCIe ExpressCard expansion board (if TI also has components to make this I would be very much interested also but I plan on just buying a ViDoc), then using the output from that graphics card hook it back up to the notebook's LCD screen and not utilizing the onboard graphics card.

Does this make sense?  And more importantly does TI have all the components to make such a thing happen assuming I know the specifications of my LCD and such.  I can get some help afterwards if I am pointed in the right direction as far as components.  Number of components is not an issue, being bulky isn't a problem, as it is going to be a bulky prototype.

Thanks in advance,

John

Richard,

I am a project trainee and i need to design a HDMI to composite convereter.I went through your post and found out that TI has a solution for

DVI to LVDS conversion.Well the HDMI to DVI conversion is possible via a cable but I don't know whether a LVDS signal will be compatible with

a LCD or not.If not , then please suggest me a LVDS to composite conversion circuit. Moreover do give the circuit and the components required for

a DVI to LVDS conversion.

with regards

Saptarshi dutta chowdhury

Saptarshi,

I need to understand the application in order to understand your need.  Are you trying to drive a panel or a monitor? 

• If you are trying to drive a monitor, usually they do not accept LVDS input signals.  Depending upon the type of Monitor many will accept HDMI, DVI, and/or VGA directly. 
• If you are developing a system that is driving a panel, these usually have a LVDS input.  Some may have parallel, DSI, or eDP inputs.   For this we need to understand the following:
  • Panel Resolution
  • Pixel Clock
  • # of bits per pixel or bits per color.
  • Single Link input or dual link input.

The components needed depend upon the answers above.

Please provide your email address so that I can put in contact with our application team. 

Regards,

Richard Hubbard

Richard

I  actually want to design a HDMI to component converter.I got a suggested solution for this.Do tell me whether this will work or not.

HDMI -----------------DVI---------------TFP401---------------  IP00C725 ------------------------THS8135--------------------------NTSC(Component)

            (via cable)                       (DVI Receiver)          (Down scaler from IChips)        (Video DAC)

I went through the datasheets of TFP401 and THS8135 but couldnot get the same for IP00C725.Do tell me if TI has any other alternatives for this IC.

Moreover TFP401 accepts DVI inputs and gives out  24 bits of even and odd RBG pixels( QE[0:23} and QO[0:23])  but  THS8135 accepts 10 bits of

RBG/YCbCr inputs, then how to interface between this two without any loss of data.

In addition to this if i directly want to connect the output of THS8135 to a TV then from where I will get the SYNC signal as there is no

HSYNC and VSYNC coming out from DAC.

Please help me out. I will soon be posting about the specifications that you want to know.

email id:saptarshi.smit@gmail.com

With regards,

Saptarshi

Saptarshi,

I am away for the office until Tuesday of next week.  We save asked our application engineer to respond to this message.  Undrea will either post here or contact you directly via the email provided above.  This may take a couple of days as we research the THS device.  We do not have any information on the IP00C725.  Here are some questions that may help though.

• Is the IP00C725 really needed?  The TFP401 can work in a single link mode and should be able to drive the THS directly.  What is driving the dual link mode aspect?
• Is the THS8134B fast enough for the application?  It is an 8-bpc DAC for VGA but supports 80MHz pixel clock. 
• We will have to think about the syncs.  It may be as simple as going directly to the VGA connector from the TFP device. 

Regards,

Richard Hubbard

Hi,

I have got several NEC LCD panels (1024x768) having 20 pins LVDS connector. It was originally used with C&T 6550  PCI to LVDS convertor add-on card to be mounted on old Intel Pentium compatible Motherboard during those time when on board VGA right on motherboards were not available. Most of them, we have purchased many years back for Embedded PC solutions at astonishing price of 1000 US$/ piece. It was no of use to us until latest motherboard started to come with direct DVI or HDMI port built right on motherboard. Most of current LCD monitor I have seen is coming with 30 pins LVDS connector may be because of 1280 x 768 size resolution.

Can I convert these DVI or HDMI to drive my 20 pins LVDS LCD panels?

Thanks in advance with regards,

--micropar--

Saptarshi,

If using the TFP401 to the THS8135, the two LSBs would be dropped.  The THS8135 generates the sync signals internally with one external sync provided along with the clock (From the TFP401).  The sync levels are carried in the outputs of the DAC.  The THS8135 datasheet and EVM guide have additional details (http://focus.ti.com/lit/ug/sleu109/sleu109.pdf).

Regards,

Undrea

Undrea,

Will TI be able to provide me with the schematic connections along with all the passive components required for TFP401A.

Regards,

Saptarshi

Richard Hubbard

Is there any EVM for TF401A available.I need that desperately and how to interface it with a THS8135 EVM as the latter

takes a analog RGB input which is then internally converted into a digital RGB via TVP7002 then again back to an analog RGB output.

Please help me out if you can.

Regards,

saptarshi

The TFP401A EVM is not available, we do have a TFP403/TFP410 EVM.  These EVM's are basically DVI repeater boards, with no external probe points or access to the data signals out of the TFP403, only DE, HSYNC, VSYNC and ODCK are accessible.