GS6042 Datasheet, PDF (11/21 Pages) Semtech Corporation – 6G UHD-SDI/3G/HD/SD Adaptive Cable Equalizer

4. Detailed Description
The GS6042 is a high-speed BiCMOS IC designed to automatically equalize
high-bandwidth serial digital video signals.
The GS6042 can equalize data rates up to 6.25Gb/s including 6G UHD-SDI, 3G SDI, HD
SDI, and SD SDI serial digital signals. The GS6042 is optimized to equalize up to 80m of
Belden 1694A cable at 5.94Gb/s (UHD-SDI), 210m at 2.97Gb/s (3G-SDI), 300m at
1.485Gb/s (HD-SDI), and 500m at 270Mb/s (SD-SDI).
The GS6042 can be powered from a single +3.3V DC power supply, and is
footprint-compatible with Semtech’s GS2974A, GS2974B, GS2984, GS2994, and GS3440
equalizers.
4.1 Serial Digital Inputs
The received serial data signal is connected to the input pins (SDI/SDI) in either a
differential or single-ended configuration. AC-coupling of the inputs is recommended
because the SDI and SDI inputs are internally biased to approximately 1.71V.
See Figure 5-1 for the recommended input applications circuit when using a
single-ended 75Ω coax cable.
4.2 Automatic (Adaptive) Cable Equalization
The input signal passes through a variable gain equalizing stage, whose frequency
response closely matches the inverse of the Belden 1694A cable loss characteristic for
any given attached cable length within the supported ranges.
The equalized signal is DC-restored, effectively restoring the logic threshold of the
equalized signal to its correct level independent of shifts due to AC-coupling.
4.3 Differential Digital Data Output
The digital data output signals (DDO/DDO) have a nominal output voltage swing of
either 850mV_ppd or 425mV_ppd (ΔV_DDO), as set by the OP_CTL pin. Table 4-1 shows the
typical output common mode voltage levels (V_CMOUT) related to the two output swing
options and the type of output transmission termination as shown in Figure 4-1 and
Figure 4-2.
GS6042
Final Data Sheet
PDS-060055
Rev. 3
May 2014
www.semtech.com
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