GS2994
GS2994 Adaptive Cable Equalizer
Key Features Description
SMPTE 424M, SMPTE 292M and SMPTE 259M The GS2994 is a high-speed BiCMOS integrated circuit
designed to equalize and restore signals received over 75
compliant
coaxial cable.
Automatic cable equalization
The device is designed to support SMPTE 424M,
Multi-standard operation from 143Mb/s to 2.97Gb/s
SMPTE292M and SMPTE 259M, and is optimized for
Performance optimized for 270Mb/s, 1.485Gb/s and
performance at 270Mb/s, 1.485Gb/s and 2.97Gb/s.
2.97Gb/s. Typical equalized length of Belden 1694A
The GS2994 features DC restoration to compensate for the
cable:
DC content of SMPTE pathological test patterns.
140m at 2.97Gb/s
The Carrier Detect output pin (CD) indicates whether a
220m at 1.485Gb/s
valid input signal has been detected. It can be connected
400m at 270Mb/s directly to the SLEEP pin to enable automatic power-down
upon loss of carrier. In the manual sleep mode, a voltage
Supports DVB-ASI at 270Mb/s
programmable threshold, which can be changed via the
Manual bypass (useful for low data rates with slow
SQ_ADJ pin, forces CD high when the input signal
rise/fall times)
amplitude falls below the threshold. This allows the GS2994
to distinguish between low-amplitude SDI signals and
Programmable carrier detect with squelch threshold
noise at the input of the device.
adjustment
The equalizing and DC restore stages are disengaged when
Automatic power-down on loss of signal
the BYPASS pin is HIGH. No equalization occurs in Bypass
Standby power <30mW (typical)
mode.
Differential outputs support DC-coupling to 1.2V, 2.5V
The GS2994 includes a gain selection pin (GAIN_SEL)
and 3.3V CML logic
which, when tied HIGH, compensates for 6dB flat
0/6 dB gain boost selection pin
attenuation.
Selectable de-emphasis: 2dB, 4dB and 6dB
The differential outputs can be DC-coupled to Gennum
Standard EIA/JEDEC logic control and status signal 3.3V cable drivers and reclockers and to industry-standard
1.2V, 2.5V and 3.3V CML logic using the VCC_O pin. In
levels
general, DC-coupling to any termination voltage between
Single 3.3V power supply operation
1.2V and 3.3V is supported.
167mW power consumption (typical)
The GS2994 also includes programmable de-emphasis with
Wide operating temperature range of -40C to +85C
three operating levels in order to support long PCB traces.
Small footprint QFN package (4mm x 4mm)
The GS2994 is footprint and drop-in compatible with
Footprint compatible with the GS2974 and the
existing GS2974 and GS2984 designs.
GS2984
The device is available in a 16-pin, 4mm x 4mm QFN
Pb-free and RoHS compliant
package.
Power consumption of the GS2994 is typically 167mW
Applications
when DC-coupled at 1.2V.
SMPTE 424M, SMPTE 292M and SMPTE 259M coaxial
The GS2994 is Pb-free, and the encapsulation compound
cable serial digital interfaces
does not contain halogenated flame retardant.
This component and all homogeneous subcomponents are
RoHS compliant.
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Data Sheet
53967 - 4 August 2012 SQ_ADJ BYPASS SLEEP CD
Squelch Adjust
Carrier Detect
VCC_O
VCC_A
Mute
DC
SDI SDO
Equalizer
Restore
SDI SDO
Output
VEE_A VEE_O
OP_CTL
AGC
AGC AGC
GS2994 Functional Block Diagram
Revision History
Version ECR PCN Date Changes and/or Modifications
4 158405 August 2012 Updates in GS2994 Pin Descriptions, Table 2-1:
DC Electrical Characteristics, and
Input/Output Circuits.
3 157635 February Added pull-down resistor to Figure 3-4.
2012 Updated the descriptions for the BYPASS and
SLEEP pins in Table 1-1. Clarification to
column headings in Table 4-1.
2 157164 November Updated the descriptions for the GAIN_SEL
2011 and SQ_ADJ pins in Table 1-1 to indicate that
they have internal pull-down resistors.
1 155124 October Converted to Data Sheet. Increased cable
2010 length to 220m at 1.485Gb/s.
0 154492 June 2010 Converted to Preliminary Data Sheet.
Updated the power and current consumption
values in Table 2-1: DC Electrical
Characteristics.
B 153758 March 2010 Removed the 470nF capacitor (between AGC
and GND) from Figure 5-1: GS2994 Typical
Application Circuit.
A 153233 January 2010 New document.
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Data Sheet
53967 - 4 August 2012