video converters

Saptarshi,

The TFP401 can output 1 pixel/clock over 24 bits, instead of even/odd.  To connect to a DAC, single pixel 24-bit should be used.

One potential issue with this is an 8-pixel latency through the DACs.  Analog RGB out will be delayed relative HS.  HS will have to be delayed somewhere in the system to compensate for this.

Sync on Green insertion using the THS8134 will requried addtional logic control for the /Sync input to insert sync on green.   HS and VS.  A Blank input signal may aslo be required.

With the THS8200, SOG can be inserted directly from the HS and VS.  HS position can alo be adjusted using I2C.  The THS8200 requires I2C programming, however.

Is sync on green a requirement?

Do you need to support only RGB graphics?

Thanks Larry

• I think i will have to operate TFP401 in 1pixel/clock mode instead of 2pixel/clock.
• How the HS be delayed using I2C control??
• Tell me which video DAC i need to use

                     (THS8135 or THS8134B or THS8200)

                     keeping in mind that TFP401 gives out 24 bits of RGB. (so probably 8 bit DAC is required) also the sync should be taken into account..

Well I need to design a HDMI to component converter so that we can interface it to a TV panel.

Now please tell me whether sync on green or sync on all channel is a requirement or not ?

Regards

Saptarshi

Saptarshi,

TVs can have YPbPr inputs or VGA RGB graphics inputs.  The color space for the two types of inputs is different.  If the RGB graphics input is used, SOG is typically not used.  If YPbPr inputs are used, sync on Y is requried. 

Do you need to support multiple types of formats, graphics and component?

Can you use only the TVs VGA graphics input connector? 

Will there be a host processor on board with I2C capability?

The THS8200 HSOUT delay can be adjusted using either dtg2_hdly or dtg2_hs_in_dly.

720p60Hz and 1080p60Hz RGB graphics fomats now exit that have the timing as 720/1080p YPbPr component.   The color space converter in the THS8200 could convert the RGB to YPbPr for display of these component formats.   Requirements will depend of how many types fo formats you need to support and what type of HDMI sources you need to support.

Regards,

Larry

Larry

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

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

Saptarshi,

I did not see an EVM in the TFP401 product folder.  You might check with TFP support or forum.

Regards,

Larry

Larry,

Please tell me one thing that in a typical DVI connecter what are the use of pins DDC SDA and SCL and whether i need to connect them with any pins of

TFP401A.I got a suggestion of connecting them wih 24LCS21-A. Will it work if i left them openas because audio and video and clock informations are carried out by TMDS channels ??

24LCS21-A is a dual mode I2C serial EEPROM??

Saptarshi

Saptarshi,

This is used for EDID DDC auto configuration using I2C communcation with an EEPROM containing supported formats.  The LVDS display interface will work without it, but the host will not know what formats can be supported by the DVI interface.

That means since i am not using a LVDS interface so i need to connect the DDC SDA and SCA to the EEPROM for letting the host know

what formats can be supported by DVI.Moreover answer me the following queries:-

1>Can i connect the ODCK clock output of TFP401A to the TVP_DATACLK input of SN74AVC32T245GKE(refer to 3.3V/1.8V level translation schematic page of EVMTHS8135)

as i am not using TVP7002 for conversion to digital RGB.I am already getting the digital RGB from TFP401.

2>Can i connect the DE output of TFP401A to the AVID input of SN74AVC32T245GKE.

Basically my design is like this:

DVI connecter---------------TFP401A--------------SN74AVC32T245GKE----------------------THS8135

Rest of the power connections and RGB,blank,clock inputs from the SN74AVC32T245GKE are connected to THS8135.

Please tell me will this work as i am going to draw the schematics and do layout design now.

Saptarshi,

Yes the same level translator can be used for the 3.3V>1.8V interface with the TFP401 clock used in place of the TVP clock and DE used in place of AVID.  Do you have a THS8135EVM that you are working with?

It is best to include the DDC circuit.

Larry

Please tell me one thing while going through the THS8135EVM power circuitry i found out that each voltage regulater has

2 o/ps Vout1 and Vout2 but both Vout1 and Vout2  itself have 2pins.Moreover 2pins of both Vout1 and Vout2 are shorted.Is it rigt to just short 2 o/p pins.

Please do tell me  if I can keep any any one of them as open?.And how to incorporate a  delay element in the digital source.

Regards

Saptarshi