S-Parameters

Hi Jamie,

  Since this is a digital device, S-Parameters is not something normally provided.  I will see if the Product Group has any information relating to insertion loss, however, since this device is also a buffer, the output is not a direct connection to the input.  If it was strictly a MUX, then yes, there would be a direct IN to OUT path, and the insertion loss could be of concern, but the DS15MB200 has an IN receiver, followed by the MUX, then driven OUT by a buffer.  Note too that there is an IBIS model on the Product Folder page: http://www.ti.com/litv/zip/snlm095 .

-Leonard   

We do measure S parameters for some of our signal integrity devices, but mostly focus on S11 and S22 to look at the impedance matching at input and output ports.

Since most of these higher speed devices are differential, we typically characterize the channels between devices, as well as the input and output as differential  S parameters.  For example  referring to them as SDD12 for the differential insertion loss or SCC21 for the common mode insertion lossFor the through parameters such as S12 and S21 - since the digital device is so highly non-linear, the S parameters do not carry much meaning.

What is it that you are trying to model with the DS64MB200?

OK, I see.

If this is digital device. Would it be accurate to say that as long as my differential input signal meets Vid (0.1-2.4Vp-p), the output would comply to the Vod in the spec (0.25-0.5Vp-p) and it's output amplitude isn't a function of input?

I need to interface to SFP module with Vid minimum 0.5Vp-p. Wrongly assumed this is an analog device and was trying to do loss analysis through backplane and DS15MB200 MUX. My SFP has built-in termination as well and I am wondering what would be the minimum Vid into my SFP. The datasheet is specifying Vod with internal termination only. If this is a digital device, I would say it would be lower then 0.5Vp-p. Is this correct?

How does Pre-emphasis affect the Vod of DS15MB200?

I am not clear on the configuration that you are trying to achieve.  You have a signal source, a backplane and an SFP module.  Are you planning on using the DS15MB200 on the side of the backplane with the SFP? - If so, then no pre-emphasis is needed or advised.  The purpose of the pre-empahsis is to give the signal high freqency boost to compensate for the high frequency loss that would be encountered in the backplane.

If you want to put the buffer on the other side of the backplane, a device like the DS100BR111 might be a better option for you.

I am using DS15MB200 to switch single SFP module between two SerDec ICs at 1.25Gbps. The SFP is co-located with the MUX, so there should be no issue here. My only issue if Vid of SFP and Vod of the DS15MB200. As I assumed before that this is an analog device, I was trying to make sure the loss through it remains low. Since, this is a digital device, I think DS15MB200 Vod will not work for my SFP with Vid of minimum 0.5Vp-p.