TFP401A schematics

kiran kumar kalsani

Other Parts Discussed in Thread: TFP401A, TFP403, SN75LVDS83A, TFP501, SN75LVDS83B, TFP401

Hi All,

I'm planning to use TFP401A in our project, this is a DVI receiver from TI. This part will actually convert DVI to RGB and then an LVDS transmitter will be used to convert the RBG signals to LVDS.

If any body out there who have used this part, please email me the pdf schematics. Email me the design files if they are made in OrCAD.

Additionally I request TI team to please share at least the schematics of the evaluation board of TFP401A.

-Kiran

over 14 years ago

0 Elias Villegas M. over 14 years ago

TI__Guru* 76130 points

Hello Kiran,

Find the information on the links below. Also, TI recommends to use TFP403 for new designs.

Regards.

http://focus.ti.com/lit/an/slla136/slla136.pdf

http://focus.ti.com/lit/an/slla134/slla134.pdf

http://focus.ti.com/lit/an/slla131/slla131.pdf

0 RE over 14 years ago

TI__Mastermind 20985 points

Hi Kiran, this application note might help you: http://www.ti.com/lit/an/slla325/slla325.pdf

Thanks,
RE

0 kiran kumar kalsani over 14 years ago in reply to RE

Intellectual 360 points

Thank you for sharing this notes. What should we do with D23 (Pin 25) on LVDS Transmitter SN75LVDS83A.

-Kiran

0 kiran kumar kalsani over 14 years ago in reply to Elias Villegas M.

Intellectual 360 points

Elias,

Thank you for advising me to use the new part TFP403. Can I get OrCAD Scheamtics for the evaluation board of this component.

I also would like to know is it mandatory to use the EEPROM in along DVI Receiver. Is it essential for functionality?

-Kiran

0 kiran kumar kalsani over 14 years ago in reply to Elias Villegas M.

Intellectual 360 points

Hello Elias,

From the app note SLLA134 I just confirmed that I do not need the EEPROM for TFP403.

I hope it will not affect any functionality. Please confirm.

In my application TFP403 is used to just convert DVI signal coming from the custom CPU designed with x86 based microprocessor.

-Kiran

0 Elias Villegas M. over 14 years ago in reply to kiran kumar kalsani

TI__Guru* 76130 points

Hello Kiran,

The unused D23 should be tied to ground.

Regards.

0 RE over 14 years ago in reply to kiran kumar kalsani

TI__Mastermind 20985 points

Kiran, that's correct that EEPROM is not used with the TFP403. With the TFP501, EEPROM is used to store HDCP keys. I don't expect that your CPU output uses HDCP.

Thanks,
RE

0 kiran kumar kalsani over 14 years ago in reply to RE

Intellectual 360 points

CPU output doesn't any HDCP since all the content that CPU sends out is actually custom GUI developed by us.

I've one question regarding the RGB outputs, if I'm using only 15" LCD which needs only one set of RGB signals can I use only even output an dleave the odd RGB open. Do I need to use any configuration pins to disable odd RGB output?

One more thing, Do I need to connect 100 ohms resistors across the + and - of the LVDS signal pair of the SN75LVDS83B? There is no information specified in the display data sheet regarding this.

0 RE over 14 years ago in reply to kiran kumar kalsani

TI__Mastermind 20985 points

Hi Kiran,

Yes, you can leave QO[23:0] disconnected. Set pin PIXS Low, for all data to come out on QE[23:0].

No, you don't need 100ohms near the LVDS83B. Please see Figure 14 in the datasheet; the positive and negative signals must terminate to 100ohms at the receiver. Many receivers have that termination integrated, and it would be good to verify that yours does.

Thanks,
RE

0 kiran kumar kalsani over 14 years ago in reply to RE

Intellectual 360 points

If I don't use EEPROM, there is no EDID. So I can't connect TFP403 based monitor to any regular CPU. I think this will be a problem.

But if I connect this monitor to my custom CPU board which already know the display information like resolution and framerate I can work without having any EDID also.

Please confirm if my above mentioned statements are right/wrong?

0 RE over 14 years ago in reply to kiran kumar kalsani

TI__Mastermind 20985 points

Hi kiran, maybe you're referring to the EEPROM that's used with the TFP501, versus no EEPROM with the TFP403. That memory is only used for HDCP keys, and not for EDID. The TFP401 simply converts TMDS to parallel data without knowledge of EDID.

Thanks,
RE

0 kusuma T J kusuma over 12 years ago in reply to Elias Villegas M.

Prodigy 20 points

Hi,

I am kusuma from tatapowersed, bangalore.

We were using the TFP401 for the HDMI to LVDS conversion so i would like to know that EEPROM to be used for EDID

0 Elias Villegas M. over 12 years ago in reply to kusuma T J kusuma

TI__Guru* 76130 points

Hello,

I don't understand your question, are you asking what EEPROM could be used for EDID?

The EDID isn’t really interfaced directly with the 401, there is an EDID ROM in the display involved with that support (Through the DDC lines).

As far as the EDID goes, the 401 is not really involved (Although the DDC lines may interface with the 401, the EDID ROM has a unique address so it has no interaction with the DVI receiver.

Regards.

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TFP401A schematics