DS90LV049: Can DS90LV049TMT support 3m cable length

Yuxi Liu(Tony)

Expert 3960 points

Part Number: DS90LV049

Tool/software:

Hi TIer

My customer want to use DS90LV049TMT to transmit the PWM signal for control at the far end.

So they want to converts the PWM signal from single signal to differential signal in cable.

And then to converts the PWM signal from differential signal to single signal in far end.

The customer wants to know if DS90LV049TMT can support a 3m cable？

I know this is about attenuation, because it is a simple PWM signal, so the signal quality requirements can be relaxed.

Do we have some experience or formula to tell me if a 3 m cable can properly transmit a PWM signal?

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 322000 points

In general, LVDS has no problems for up to 10 m.

0 Amy over 1 year ago

TI__Genius 15321 points

Hello,

LVDS should be fine at 3m. The transmission distance would only be limited if general LVDS design guidelines per the datasheet were violated. Be sure that all datasheet recommendations are followed, such as using cables and connectors with a matched differential impedance of 100 ohm and do not introduce any major impedance discontinuities. Per the datasheet, if the traces are not on the same board and cabling is used, balanced cables (e.g. twisted pair) are usually better than unbalanced cables (ribbon cable, simple coax.) for noise reduction and signal quality. Balanced cables tend to generate less EMI due to field canceling effects and also tend to pick up electromagnetic radiation a common-mode (not differential mode) noise which is rejected by the receiver.

Thank you, Amy

0 Yuxi Liu(Tony) over 1 year ago in reply to Amy

TI__Expert 3960 points

Hi TIer

Thank you for your reply.

I see DS90LV049 which can use in source.

Do you have some recommend chip which used in sink?

Thank you very much.

And Do you have some retimer chip recommended?

0 Amy over 1 year ago in reply to Yuxi Liu(Tony)

TI__Genius 15321 points

Hello,

I have been out of office and I will get back to you this week.

Thank you, Amy

0 Amy over 1 year ago in reply to Yuxi Liu(Tony)

TI__Genius 15321 points

Hello,

The DS90LV049 has a fail-safe feature that is designed to source/sink a small amount of current.

It appears that retimers are part of another group: Ethernet retimers, redrivers & mux-buffers | TI.com

I am not familiar with these devices, so I would recommend posting your question on their forum.

Regards, Amy

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DS90LV049: Can DS90LV049TMT support 3m cable length