SN65LVDT100: LVDS level shifter

Shoo Saga

Intellectual 1931 points

Part Number: SN65LVDT100

HI Team,

My customer is looking for LVDS level shifter. The requirements are below.

Input

・LVDS

・VCM:0.55V

・Vp-p:450mV

output

・LVDS

・VCM:0.9V

・Vp-p:300mV

This device can support above the requirements?

Thanks,

Shoo

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 276360 points

This device (like almost any other LVDS transmitter) outputs a common-mode voltage of about 1.2 V.

But in general, LVDS level shifting is not necessary; LVDS receivers accept a wide range of common-mode voltages, and any peak-to-peak voltage of more than 100 mV.

I suspect you can simple connect this input to this output. Where exactly do these requirements come from?

0 Shoo Saga over 1 year ago in reply to Clemens Ladisch

TI__Intellectual 1931 points

Hi Clemens,

Receiver cannot support 0.9V VCM. that's why they need voltage translator or protocol translator. Do we have any alternative solution for that?

Thanks,

Shoo

+1 David (ASIC) Liu over 1 year ago in reply to Shoo Saga

TI__Guru**** 156181 points

Shoo-san

Please see this app note, https://www.ti.com/lit/an/slaa840/slaa840.pdf. You can use AC coupling to address the common mode voltage difference.

Thanks

David

0 Shoo Saga over 1 year ago in reply to David (ASIC) Liu

TI__Intellectual 1931 points

Hi David,

They mentioned cannot use AC coupling due to the limitation. Anyway got it. Thanks.

Thanks,

Shoo

+1 David (ASIC) Liu over 1 year ago in reply to Shoo Saga

TI__Guru**** 156181 points

Shoo-san

The LVDS buffer output common mode voltage is shown below.

If they want to support 0.9V only, then I would recommend using AC coupling capacitor.

Thanks

David

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SN65LVDT100: LVDS level shifter