SN65LVDS2: no output with a different clock input, AC coupled

weigang Fu

Prodigy 30 points

Part Number: SN65LVDS2

A/B pins measured a low +0.268V, high +0.668V diff clock, but no output on R pin

i think Vid -0.4V/+0.4V and Vcm 0.468V are both compatible with spec requirement

A/B pin are terminated with an external 100Ohm.

then what's the issue?

over 4 years ago

0 Ikechukwu Anyiam over 4 years ago

TI__Mastermind 35130 points

Hi Weigang,

Can you provide scope captures of the input waveforms?

Also, if you remove the AC coupling caps and DC couple the connection, are you able to get an output?

Regards,

I.K.

0 weigang Fu over 4 years ago in reply to Ikechukwu Anyiam

Prodigy 30 points

Hi, I.K.

the driver Vcm is out range of the receiver requirement, DC couple may be not accept.

is there any document that show the internal circuit of sn65lvds2? or any application note for this part?

here is the scope capture on PIN A/B

0 Ikechukwu Anyiam over 4 years ago in reply to weigang Fu

TI__Mastermind 35130 points

Hi Weigang,

That signal looks okay - very strange that it's not working. When you say that there's "no output" on the R pin, is that signal stuck low or high? Also, have you checked the power/ground on the device?

We can't share internal circuits of the device, but there is application information starting on page 19 of the datasheet.

Regards,

I.K.

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SN65LVDS2: no output with a different clock input, AC coupled