GS6042 Datasheet, PDF (14/21 Pages) Semtech Corporation – 6G UHD-SDI/3G/HD/SD Adaptive Cable Equalizer

4.7 Adjustable Output Swing, De-emphasis, and Mute
The OP_CTL input pin determines the output swing and de-emphasis settings for DDO
and DDO.
The OP_CTL pin is an analog input, allowing different combinations of output swing,
de-emphasis, and mute. The possible values are listed in Table 4-5.
Table 4-5: OP_CTL Functions and Levels
Level
0
1
2
3
4
5
6
7
8
Swing
850mV_ppd
850mV_ppd
850mV_ppd
850mV_ppd
425mV_ppd
425mV_ppd
425mV_ppd
425mV_ppd
425mV_ppd
De-emphasis
Off
2dB
6dB
8dB
Off
2dB
6dB
8dB
N/A
Mute
N
N
N
N
N
N
N
N
Y
Voltage (V)
0.000 - 0.083
0.234 - 0.394
0.545 - 0.704
0.856 - 1.015
1.166 - 1.333
1.484 - 1.644
1.795 - 1.954
2.106 - 2.265
2.416 - 2.500
When muted, the output swing is set to 425mV_ppd and the outputs are latched.
Automatic muting of the output can be enabled by connecting the CD pin to the
OP_CTL pin.
If the connection is made directly, as shown in Figure 4-3, the output would be in its
default mode (850mV_ppd swing with no de-emphasis) when there is signal present.
Figure 4-3: Direct Loopback
To enable automatic muting while the output is configured for other settings, a resistor
network can be used between CD and VCC_A. The intermediate voltages of this resistor
ladder can set the output to any one of the nine different settings as shown in the
examples given in Figure 4-4 and Figure 4-5.
GS6042
Final Data Sheet
PDS-060055
Rev. 3
May 2014
www.semtech.com
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