Extended Reach 3G/HD/SD Adaptive Cable Equalizer
Key Features Applications
SMPTE ST 424, SMPTE ST 292 and SMPTE ST 259 SMPTE ST 424, SMPTE ST 292 and SMPTE ST 259
compliant coaxial cable serial digital interfaces
Automatic cable equalization
Multi-standard operation from 125Mb/s to 2.97Gb/s
The GS3440 is a high-speed BiCMOS device designed to
Performance optimized for 270Mb/s, 1.485Gb/s and
equalize and restore signals received over 75 coaxial
2.97Gb/s. Typical equalized length of Belden 1694A
cable up to:
The device is designed to support SMPTE ST 424,
210m at 2.97Gb/s
SMPTE ST 292 and SMPTE ST 259, and is optimized for
300m at 1.485Gb/s performance at 270Mb/s, 1.485Gb/s and 2.97Gb/s.
550m at 270Mb/s
The GS3440 features DC restoration to compensate for the
DC content of SMPTE pathological signals.
Supports DVB-ASI at 270Mb/s
The Carrier Detect output pin (CD) indicates whether an
Supports MADI at 125Mb/s
input signal has been detected. It can be connected directly
Manual bypass (useful for low data rates with slow
to the SLEEP pin to enable automatic sleep on loss of carrier.
A voltage programmable threshold, set via the SQ_ADJ pin,
Programmable carrier detect with squelch threshold
forces CD high when the input signal amplitude falls below
the threshold. This allows the GS3440 to distinguish
Automatic power-down on loss of signal
between low-amplitude SDI signals and noise at the input
of the device.
Standby power <35mW (typical)
The equalizing and DC restore stages are disengaged and
Differential output supports DC-coupling from 1.2V to
no equalization occurs when the BYPASS pin is HIGH.
3.3V CML logic
Setting the BYPASS pin HIGH is useful for signals launched
Option to compensate for 6dB flat attenuation prior to
at the signal source with low data rates and/or slow rise/fall
input of device
Selectable output de-emphasis: 2dB, 4dB and 6dB
The GS3440 features a gain selection pin (GAIN_SEL) which
Standard EIA/JEDEC logic control and status signal
can be used to compensate for 6dB flat attenuation prior to
levels the input of the device.
Single 3.3V power supply operation
The differential output can be DC-coupled to Semtechs
reclockers and cable drivers, as well as industry-standard
180mW power consumption (typical)
1.2V, 1.8V, 2.5V and 3.3V CML logic by changing the voltage
Wide operating temperature range of -40C to +85C
applied to the VCC_O pin. In general, DC-coupling to any
Small footprint QFN package (4mm x 4mm)
termination voltage between 1.2V and 3.3V is supported.
Footprint compatible with the GS2974A, GS2974B,
The GS3440 also features programmable output
GS2984 and GS2994
de-emphasis with three, user-selectable operating levels to
support long PCB traces at the output of the device.
Pb-free and RoHS compliant
GS3440 Adaptive Cable Equalizer 1 of 23
Final Data Sheet
Rev. 2 December 2012 Proprietary and ConfidentialDescription (continued)
The device comes in a 16-pin, 4mm x 4mm QFN package and is footprint compatible with Semtechs GS2974A, GS2974B,
GS2984 and GS2994 equalizers.
Power consumption of the GS3440 is typically 180mW when DC-coupled at 1.2V.
The GS3440 is Pb-free, and the encapsulation compound does not contain halogenated flame retardant.
This component and all homogeneous subcomponents are RoHS compliant.
SQ_ADJ BYPASS SLEEP CD
SDI DC DDO
GS3440 Functional Block Diagram
GS3440 Adaptive Cable Equalizer 2 of 23
Final Data Sheet
Rev. 2 December 2012 Proprietary and Confidential