SN75LVDS83B: Connection

Uilter Witte

Intellectual 300 points

Part Number: SN75LVDS83B

Hi,

We are using SN75LVDS83B to convert RGB (18 bits CPU) to a 10.1 display LVDS (24 bits) display.

We facing problems with the image. The colors is not good and there is a lot of noises either.

The image below is the linux boot sequence. Note there is a noise on Tux image.

The next is the linux desktop. It should be like this - docs.toradex.com/101143-image-toradexlinuxdesktop.jpg

Next image is the schematic and connections.

Note we connect the Y3 signal, but nothing changes.

Any one here already have this problem?

We appreciate any help!
Thanks!

over 4 years ago

0 Hamzeh Jaradat over 4 years ago

TI__Guru* 92000 points

Hello Uilter,

I will review your schematics and come back to you by tomorrow.

0 Uilter Witte over 4 years ago in reply to Hamzeh Jaradat

Intellectual 300 points

Hello Hamzeh,

Thank you for this!

I attached the display datasheet for you. Hope this help you too.

GBE101WX02J.pdf

Regards,

Uilter

0 Hamzeh Jaradat over 4 years ago in reply to Uilter Witte

TI__Guru* 92000 points

Hello Uilter,

I have checked your schematic. Everything looks fine.
Please make sure the power supply noise on any VCC pin is not exceeding the max allowed limit (100mV P-P)
Also make sure you are following the power-up sequence shown in section 10.2.2.1
Make sure you maintain the max. Input PCLK jitter and timing parameters shown in section 7.8

0 Uilter Witte over 4 years ago in reply to Hamzeh Jaradat

Intellectual 300 points

Hamzeh,

The power supply have some ripple. I replace it and make sure to not exceed the limit.
This not solved the noises, the image still the same.

About the power-up sequence, we are investigating.

The PCLK are configured to 65MHz.

While we investigate the previous topics, do you have other recommendation or advice?

Regards,

Uilter.

0 Hamzeh Jaradat over 4 years ago in reply to Uilter Witte

TI__Guru* 92000 points

Hello Uilter,

you may need also to check your layout of the Inputs and the differential pairs at the output. Make sure you do not have any other noise source near these to prevent cross talking.

Interface

Interface forum

SN75LVDS83B: Connection