GV7704 Datasheet, PDF (18/52 Pages) Semtech Corporation – Quad HD-VLC Receiver

Table 4-1: Typical Cable Length Performance
Data Rate
HD data
@ 1.485Gb/s
HD-VLC encoded data
@ 270Mb/s
Belden 543945 CCTV
Coaxial
150m
550m
Cat-5e/6 UTP
N/A
150m
The Serial Data Signal may be connected to the input pins of any of the four channels in
either a differential or single ended configuration. Only AC coupling of the inputs is
supported, as the SDI and SDI inputs are internally biased at approximately 1.8V.
Note: The serial data output should be disabled to achieve maximum SDI cable reach.
4.2.1 Input Termination Selection
Each of the four channels can be individually configured to work in either 50Ω or 75Ω
input termination. Please refer to Register Map for details.
4.2.2 Automatic Signal Rate Detection
The device is able to automatically detect the rate of the incoming video signal. There
are two data rates which are supported:
• HD-VLC encoded 270Mb/s (including 270x1.001Mb/s)
• HD-SDI 1.485Gb/s (including 1.485÷1.001Gb/s)
The detected rate is indicated in bit SD_HDB in register GEN_VIDEO_CFG_0_REG which
specify whether the incoming signal is HD-VLC encoded (270Mb/s) or HD (1.485Gb/s).
4.3 Serial Digital Outputs
The GV7704’s serial data output pins, SDO and SDO, provide complementary outputs,
each capable of driving at least 800mV into a 75Ω single-ended load.
Compliance with all requirements defined in Section 4.3.1 through Section 4.3.2 is
guaranteed when measured across a 75Ω terminated load at the output of 1m of Belden
543945 cable, including the effects of the BNC and coaxial cable connection, except
where otherwise stated.
Figure 4-1 illustrates this requirement.
GV7704
Coupling
Capacitor
1m Belden 543945
75Ω coaxial cable
Measuring Device
75Ω
BNC
BNC
resistive
load
Figure 4-1: BNC and Coaxial Cable Connection
GV7704
Preliminary Data Sheet Rev.3
PDS-060376
September 2015
www.semtech.com
18 of 52
Semtech