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2.2.2 GS3490 Cable Driver Transmitter Model
The GS3490 cable driver transmitter IBIS-AMI model consists of three parts: (1) the
Analog Driver IBIS model, (2) the Transmitter AMI model, and (3) the QFN package
model. The block diagram in
individual parts of the model.
Analog
AMI
Term
IBIS-AMI Model
Figure 2-7: GS3490 Cable Driver Transmitter IBIS-AMI Model
The Analog Driver IBIS model receives processed signal information from the
Transmitter AMI model and applies the analog characteristics of the GS3490 cable driver
transmit driver. Two different sub-models have been employed for different output
slew rates. The appropriate sub-model has to be selected regarding the SD_EN input pin
using the
Table
2-2.
Table 2-2: Sub-model Selection Based on the Output Slew Rate
SD_EN
0
1
The GS3490 cable driver transmitter AMI model consists of RSET parameter to control
the output driver swing. This parameter is the same as R
Sheet. For a typical 800mV
range is from 1.21kΩ to 576Ω which translates to 500mV
In order to determine the RSET value, you can use the following equation:
Where R
is the value of the termination resistors and V
term
output voltage swing. For more information regarding the R
the GS3490 Data Sheet.
As stated in
Section
2.2.2, a differential model is developed for the GS3490 cable driver
transmitter. Therefore, the GS3490 cable driver transmitter QFN package model is
provided as a 4-Port S-parameter file (GS3490_SDO.s4p) in standard touchstone format
from 0GHz to 15GHz 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.
GS3490
User Guide
Rev.0
PDS-060922
January 2015
Figure 2-7
shows the sequence of the signal flow and the
QFN Package
(S-parameters)
Rise/Fall Time
SMPTE 424M & 292M compliant
SMPTE 259M compliant
output, RSET should be set to 750Ω. The RSET parameter
pp
R
⎛
term
×
-----------------------
=
8
RSET
⎝
V
outppSE
www.semtech.com
To Channel
Sub-Model
sdo_HD
sdo_SD
resistor in GS3490 Data
SET
to 1040mV
output swing.
pp
pp
⎞
⎠
is the single-ended
outppSE
resistor, please refer to
SET
6 of 7
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