GS2974B HD-LINX™ III Adaptive Cable Equalizer
Features
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SMPTE 424M, SMPTE 292M, 344M and SMPTE 259M
compliant
Automatic cable equalization
Multi-standard operation from 143Mb/s to 2.97Gb/s
Supports DVB-ASI at 270Mb/s
Small footprint (4mm x 4mm)
Pb-free and RoHS compliant
Manual bypass (useful for low data rates with slow
rise/fall times)
Performance optimized for 1.485Gb/s and 2.97Gb/s
Typical equalized length of Belden 1694A cable: 140m
at 2.97Gb/s, 230m at 1.485Gb/s, and 250m at 270Mb/s
50Ω differential output (internal 50Ω pull-ups)
Programmable mute based on max cable length adjust
Single 3.3V power supply operation
Operating temperature range: 0°C to +70°C
Footprint compatible with GS2974A and GS1574A
Description
The GS2974B is a high-speed BiCMOS integrated circuit
designed to equalize and restore signals received over 75Ω
co-axial cable.
The GS2974B is designed to support SMPTE 424M, SMPTE
292M and SMPTE 259M, and is optimized for performance
at 1.485Gb/s and 2.97Gb/s.
The GS2974B features DC restoration to compensate for the
DC content of SMPTE pathological test patterns.
A voltage programmable mute threshold (MCLADJ),
applicable for SD mode (refer to
Section 4.3),
is included to
allow muting of the GS2974B output when an approximate
selected cable length is reached for SMPTE 259M signals.
This feature allows the GS2974B to distinguish between
low amplitude SD-SDI signals and noise at the input of the
device. The serial digital outputs of the GS2974B may be
forced to a mute state by applying a voltage to the MUTE
pin.
Power consumption is typically 215mW using a 3.3V
power supply. The GS2974B is lead-free, and the
encapsulation compound does not contain halogenated
flame retardant.
This component and all homogeneous subcomponents are
RoHS compliant.
Applications
•
SMPTE 424M, SMPTE 292M and SMPTE 259M Coaxial
Cable Serial Digital Interfaces.
MCLADJ
CABLE LENGTH ADJUSTOR
CARRIER DETECT
MUTE
CD
MUTE
BYPASS
SDI
SDI
EQUALIZER
DC RESTORE
OUTPUT
SDO
SDO
AGC
GS2974B Functional Block Diagram
GS2974B GS2974B HD-LINX™ III Adaptive Cable
Equalizer
Data Sheet
45062 - 3
April 2009
www.gennum.com
1 of 17
Revision History
Version
3
ECR
151788
PCN
−
−
Date
April 2009
Changes and/or Modifications
Corrected
250pc part number in
6.6 Ordering
Information.
Added 2500pc reel size to
6.6 Ordering
Information.
Added the maximum power
consumption in
Table 2-1: DC Electrical
Characteristics.
Changed
the Output Voltage
Swing
from 550mV
p-p
to 600mV
p-p
in
Table
2-2: AC Electrical
Characteristics.
Converted
to Data
Sheet.
Updated document
format. Re-wrote section
4.3 Programmable
Maximum
Cable
Length Adjust (MCLADJ).
Added Tape and Reel to
6.6 Ordering
Information.
Converted
to Preliminary Data
Sheet.
Changed
Input ESD Voltage to 4kV in
2.1
Absolute Maximum Ratings.
Replaced
5.3
Typical Application
Circuit.
Addition of
High
Gain
Adaptive
Cable
Equalizers on page 12,
and removal of
Typical
Application
Circuit
on page 13.
New document.
2
151333
January
2009
1
149533
−
April 2008
0
148227
–
November
2007
B
146732
–
August 2007
A
145689
–
July
2007
GS2974B GS2974B HD-LINX™ III Adaptive Cable
Equalizer
Data Sheet
45062 - 3
April 2009
2 of 17
Contents
Features.................................................................................................................................................................1
Applications.........................................................................................................................................................1
Description...........................................................................................................................................................1
Revision History .................................................................................................................................................2
1. Pin Out...............................................................................................................................................................4
1.1 GS2974B Pin Assignment ...............................................................................................................4
1.2 GS2974B Pin Descriptions .............................................................................................................4
2. Electrical Characteristics ............................................................................................................................6
2.1 Absolute Maximum Ratings ..........................................................................................................6
2.2 DC Electrical Characteristics ........................................................................................................6
2.3 AC Electrical Characteristics ........................................................................................................7
Test Circuit ...........................................................................................................................................................8
3. Input/Output Circuits ..................................................................................................................................8
4. Detailed Description.....................................................................................................................................9
4.1 Serial Digital Inputs .........................................................................................................................9
4.2 Cable Equalization ........................................................................................................................ 10
4.3 Programmable Maximum Cable Length Adjust (MCLADJ) ............................................. 10
4.4 Mute and Carrier Detect .............................................................................................................. 11
5. Application Information .......................................................................................................................... 12
5.1 High Gain Adaptive Cable Equalizers .................................................................................... 12
5.2 PCB Layout ....................................................................................................................................... 12
5.3 Typical Application Circuit ........................................................................................................ 13
6. Package & Ordering Information .......................................................................................................... 14
6.1 Package Dimensions ..................................................................................................................... 14
6.2 Packaging Data ............................................................................................................................... 14
6.3 Recommended PCB Footprint ................................................................................................... 15
6.4 Marking Diagram ........................................................................................................................... 15
6.5 Solder Reflow Profiles .................................................................................................................. 16
6.6 Ordering Information ................................................................................................................... 16
GS2974B GS2974B HD-LINX™ III Adaptive Cable
Equalizer
Data Sheet
45062 - 3
April 2009
3 of 17
1. Pin Out
1.1 GS2974B Pin Assignment
V
CC
_A
MUTE
V
CC
_D
13
12
V
EE
_D
11
GS2974B
(top view)
SDI
3
10
SDO
CD
15
16
V
EE
_A
1
14
SDI
2
SDO
V
EE
_A
4
5
AGC
6
AGC
7
BYPASS
8
MCLADJ
9
V
EE
_D
Center Pad
(bottom of package, internally
bonded
to VEE_A)
Figure 1-1: 16-Pin QFN
1.2 GS2974B Pin Descriptions
Table 1-1: GS2974B Pin Descriptions
Pin Number
1, 4
Name
VEE_A
Timing
Analog
Type
Power
Description
Most negative power supply for analog circuitry.
Connect
to
GND.
2, 3
5, 6
SDI, SDI
AGC, AGC
Analog
Analog
Input
–
Serial
digital differential input.
External AGC capacitor.
Connect
pin 5 and pin 6 together as shown in the
Typical
Application
Circuit
on page 13.
7
BYPASS
Not
Synchronous
Analog
Input
Forces the Equalizing and DC RESTORE stages into bypass mode
when HIGH. No equalization occurs in this mode.
Maximum cable length adjust.
Adjusts the approximate maximum amount of cable to be
equalized.
See
Section
4.3.
and
Section
4.4
8
MCLADJ
Input
9
VEE_D
Analog
Power
Most negative power supply for the digital circuitry and output
buffer.
Connect
to
GND.
GS2974B GS2974B HD-LINX™ III Adaptive Cable
Equalizer
Data Sheet
45062 - 3
April 2009
4 of 17
Table 1-1: GS2974B Pin Descriptions (Continued)
Pin Number
10, 11
12
Name
SDO, SDO
VEE_D
Timing
Analog
Analog
Type
Output
Power
Description
Equalized serial digital differential output.
Most negative power supply for the digital circuitry and output
buffer.
Connect
to
GND.
13
VCC_D
Analog
Power
Most positive power supply for the digital I/O pins of the device.
Connect
to +3.3V DC.
14
MUTE
Not
Synchronous
Input
CONTROL SIGNAL
INPUT
levels are LVCMOS/LVTTL compatible. (3.3V Tolerant)
Controls
output behaviour on
SDO
and
SDO
See
Section
4.4.
15
CD
Not
Synchronous
Output
STATUS SIGNAL
OUTPUT
Signal
levels are LVCMOS/LVTTL compatible.
Indicates the presence of a good input signal.
See
Section
4.4.
16
VCC_A
Analog
Power
Most positive power supply for the analog circuitry of the device.
Connect
to +3.3V DC.
–
Center
Pad
–
Power
Internally bonded to VEE_A.
GS2974B GS2974B HD-LINX™ III Adaptive Cable
Equalizer
Data Sheet
45062 - 3
April 2009
5 of 17
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