DS90C385A: DS90C385A connect with LVDS screen

Sulyn ZHANG

Part Number: DS90C385A

Hi Team,

My customer is using DS90C385A to connect to LVDS screen. I have a post before which already been closed. So I post a new one here.

DS90C385A's common voltage is about 1.25V, but customer used LVDS screen's common mode voltage is about 1.65V, as below:

So will this work or any suggestions to make it work? Thanks for your support!

Best regards,

Sulyn

over 7 years ago

0 Ikechukwu Anyiam over 7 years ago

TI__Mastermind 35130 points

Hi Sulyn,

I believe there is a way to make this work with external components, similar to the scheme on page 2 of this app note: www.ti.com/.../scaa056.pdf

I will write a detailed response by tomorrow.

Regards,
I.k.

0 Sulyn ZHANG over 7 years ago in reply to Ikechukwu Anyiam

TI__Expert 8700 points

Hi I.K. Anyiam,

Thanks for your support, would you help give suggested external components for this case, thanks!

LVDS screen's common mode voltage is about 1.65V while our DS90C385A's output common mode voltage is 1.25V, need external components to level-shift, thanks.

Best regards,

Sulyn

0 Ikechukwu Anyiam over 7 years ago in reply to Sulyn ZHANG

TI__Mastermind 35130 points

Hi Sulyn,

Sorry for the delay. Assuming Vcc = 3.3V they can use the resistor scheme below (taken from Figure 9 of this document): http://www.ti.com.cn/cn/lit/an/scaa062/scaa062.pdf

Except in your case, to keep each lane 50 ohms you would replace the 83 ohm resistors with 91 ohm resistors, and replace the 130 ohm resistors with 110 ohm resistors. With this the common mode voltage should be around 1.8V which is within specification of the display datasheet, and each lane is still 50 ohms. Keep in mind that you would not use a 100 ohm termination resistor with the above scheme.

Regards,

I.K.

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DS90C385A: DS90C385A connect with LVDS screen