GS3490
User Guide
Rev.0
PDS-060922
January 2015
3 of 7
Propietary & Confidential
www.semtech.com
2.1.1 GS3490 Cable Equalizer Receiver Model
The GS3490 cable equalizer receiver IBIS-AMI model consists of three parts: (1) the
Analog Termination IBIS model, (2) the Receiver AMI model and (3) the QFN package
model. The block diagram in
Figure 2-3
shows the sequence of signal flow and the
individual parts of the model. The external S-parameter file for the QFN Package model
extends the accuracy of the package effects beyond which can be described by R, L and
C components in the current IBIS 5.0 standard. The external S-parameter data is
processed as part of the channel by the EDA platforms.
Figure 2-3: GS3490 Cable Equalizer Receiver IBIS-AMI Model
The receiver IBIS model provides the characterized GS3490 cable equalizer receiver
input termination which is used by the EDA platform to determine the time-domain
impulse response for the channel. The model is based on a single-ended non-inverting
characterization of the GS3490 Cable Equalizer Receiver and the EDA platform develops
a differential model from complimentary copies of the single-ended model. Note that
the IBIS model only contains the DC termination impedance of the receiver (I-V tables in
IBIS file) and doing frequency dependent simulations (e.g. return loss simulations) using
the IBIS file is not very accurate. In these cases, the "SDI_term.s2p" s-parameter file can
be used to capture the frequency dependent input impedance of the GS3490 cable
equalizer receiver.
The GS3490 cable equalizer receiver AMI model only includes the slicer. The adaptive
equalizer and Belden cable model are not included in the AMI model and the users
should add the deterministic jitter to their test-bench based on the Belden cable length
that they are using and GS3490 datasheet. For example, if the cable length is 140m and
the data rate is 2.97Gb/s, typical output jitter and maximum output jitter are 0.2UI and
0.45UI based on GS3490 datasheet. These values should be added to the test-bench to
have more accurate results.
The GS3490 cable equalizer receiver QFN package model is provided as a 4-Port
S-parameter file (GS3490_SDI.s4p) in standard touchstone format from 0GHz to 15 GHz
with 1501 data points.
Note:
The package model does not include the application circuit and an appropriate
application circuit must be used in the simulation Testbench along with the IBIS-AMI
model. A typical application circuit can be found in the GS3490 Data Sheet.
Analog
Term
QFN Package
(S-parameters)
AMI
From Channel
IBIS-AMI Model
