GS2994 Datasheet, PDF (14/20 Pages) Semtech Corporation – GS2994 Adaptive Cable Equalizer

Table 4-3: CD Output Table
CD
Input Status
0
Valid Input on SDI, SDI pins
1
Input is not valid
4.6 GAIN_SEL
The GS2994 has an option of compensating for 6dB of flat attenuation in applications
where there has been some type of attenuation prior to the equalizer.
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Table 4-4: GAIN_SEL Input Table
GAIN_SEL Function
0
No flat band gain is applied
1
6dB of flat attenuation will be
compensated by the equalizer.
4.7 Adjustable Output Swing, De-Emphasis and Mute
With the GS2994, the OP_CTL input pin determines the output swing and de-emphasis
settings.
The OP_CTL pin is an analog input to allow different combinations of output swing,
de-emphasis and mute. The possible values are listed in Table 4-5 below:
Table 4-5: OP_CTL Functions and Levels
Level
0
1
2
3
4
5
6
7
8
Swing
800mV
800mV
800mV
800mV
400mV
400mV
400mV
400mV
400mV
De-emphasis
Off
2dB
4dB
6dB
Off
2dB
4dB
6dB
N/A
Mute
N
N
N
N
N
N
N
N
Y
Voltage
0
1 x (VCC_A/8)
2 x (VCC_A/8)
3 x (VCC_A/8)
4 x (VCC_A/8)
5 x (VCC_A/8)
6 x (VCC_A/8)
7 x (VCC_A/8)
VCC_A
Auto_mute can be enabled by connecting CD to OP_CTL through external components,
such that when CD is HIGH (2.5V), OP_CTL is forced HIGH (3.3V) and when CD is LOW
GS2994 GS2994 Adaptive Cable Equalizer
Data Sheet
53967 - 4
August 2012
14 of 20