DS250DF230: Insertion loss budget

Ohad Bonneh

Intellectual 1970 points

Part Number: DS250DF230
Other Parts Discussed in Thread: DS250DF410

Tool/software:

Hi Team,

We have few questions regarding the DS250DF230.

1) we would like to understand how to calculate the insertion loss budget, how do i know what will be the allowable jitter to my signal to ensure signal integrity using the retimer?

2) what is the function of the signal detect? in the DS there is a short paragraph on it but we want to deeper understand what is the purpose of this function and what it do.

3) since we are not using PCIe there is a specific data rate that we are using which is not a conventual - 6.375Gbps can you explain what is the ref clock that we need to use? is it matter? do we need to take something into account?

thanks!

2 months ago

0 Drew Miller1 2 months ago

TI__Mastermind 36793 points

Hi Ohad,

The DS250DF230 can support up to 35 dB of loss at 12.9 GHz. I'd recommend performing simulation with the IBIS-AMI model to better understand system performance.
The signal detect function is used to identify when a signal is present on the RX pins and turn on the channel accordingly.
You can use either cal clk rate. Please see the programming guide for details on configuring the DS250DF230 for 6.375 Gbps.

Thanks,

Drew

0 Ohad Bonneh 2 months ago in reply to Drew Miller1

TI__Intellectual 1970 points

Hi Drew,

we understand that the IBIS-AMI simulations files for this device are intended for the ADS simulation tool.
Since we are using HyperLynx, do you know which modifications do we need to do in order to run the simulations smoothly?

thanks!

0 David Creger 2 months ago in reply to Ohad Bonneh

TI__Mastermind 27122 points

Hi Ohad,

Drew is out of office. Someone on my team will get back shortly.

Thanks,

David

0 Undrea Fields 2 months ago in reply to David Creger

TI__Genius 11480 points

Hi,

My understanding is that HyperLynx supports IBIS-AMI models. Do you have an issue you are seeing with the model in HyperLynx?

Regards,

Undrea

0 Ohad Bonneh 2 months ago in reply to Undrea Fields

TI__Intellectual 1970 points

We cannot change any parameters, no matter what we do we are getting the same results.

are we familiar with any issues with this model at hyperlynx?

0 Ohad Bonneh 1 month ago in reply to Ohad Bonneh

TI__Intellectual 1970 points

we would really need help here,
This is holding us back from moving forward with the device.

0 Undrea Fields 1 month ago in reply to Ohad Bonneh

TI__Genius 11480 points

Hi Ohad,

In the modeling, does the customer set CTLEAdapt to "0", and then enter the CTLE value? In ADS the eye also does not change unless the CTLEAdapt value is changed as well.

Regards,

Undrea

0 Ohad Bonneh 1 month ago in reply to Undrea Fields

TI__Intellectual 1970 points

Hi Undrea,

Yes, we set CTLEAdapt to "0", manually entered the CTLE value, and the problem still occurred.

Until issue #1 is resolved, could you please recommend a similar retimer that uses the same SerDes PHY? This would allow us to use it as an alternative model in HyperLynx
In case that issue#1 cannot be resolved, and there is no similar retimer with similar SerDes PHY, is it possible that we will perform simulations for the customer with thier special requirements?

0 Undrea Fields 1 month ago in reply to Ohad Bonneh

TI__Genius 11480 points

Hi Ohad,

I'll get with the team in SC this morning for an alternative model.

Thanks for confirming, when using ADS, I do see the effect of changing CTLE values. The models are verified with ADS but not Hyperlynx, but this version of IBIS-AMI model should be compatible from what I've found.

Other than the source, the main difference in the schematics is the external termination added in the ADS schematic.

Regards,

Undrea