DS90LV012A: DS90LV012A

Hi Joseph,

DS90LV012A is not a switch, it's a unidirectional LVDS receiver meant for point-to-point communication. For bi-directional communication you will need to use a passive switch: https://www.ti.com/switches-multiplexers/analog/overview.html 

Regards,

I.K. 

Hi, yes, sorry for mentioning the wrong PN, the switch I'm using is HD3SS3411IRWA.

My signals type are CML and this switch can accept LVDS or other types but not CML

Do you have any suggestions please for the proper termination and since it's bidirectional should I add the termination to both sides ? since even port A is CML in my design. 

Thanks in advance,

Joseph 

it should work for CML signal as long as common mode voltage is <2v.

Any biasing is needed or specific termination ?

I have a comment from the customer to target a 1.0V V_CM, using a resistor bias network which has an impedance >> characteristic impedance of the lines, Do you have any more details or recommendation for this note ?

Thanks,

Joseph 

if CML is on both sides of the mux, there are no need for additional biase for termination, what is their impedance?

Its 100 ohm differential 

this is ideal  impedance,

if they target 1v CM , pullup termination is 50 ohm for each single signal.

thanks for your feedback, one more comment, is there any reason for this comment from my customer ?

"For that rebias, my suggestion was to target 1.0V V_CM, using a resistor bias network which has an impedance >> characteristic impedance of the lines."

your suggest R value is = the trace impedance while he is asking for larger value, any idea about this comment ?

Thanks,

Joseph 

they want to biase, it should  be 50 ohm for CML

So in this case it;s only a 50 ohm pull up resistor to 3.3V ?

Also from both sides or only from one side ?

Thanks

you mentioned 1v before, not 3.3v