GS2993 Datasheet, PDF (16/23 Pages) Gennum Corporation – Automatic power-down on loss of signal

4.6 GAIN_SEL
The GS2993 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 GS2993, the OP1_CTL input pin determines the output swing and de-emphasis
settings for the first output, with OP2_CTL controlling the second output.
The OP1_CTL and OP2_CTL pins are both analog inputs to allow different combinations
of output swing, de-emphasis and mute. The possible values are listed in Table 4-5
below:
Table 4-5: OP1_CTL and OP2_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 (V_{CC_A})/8
2 x (V_{CC_A})/8
3 x (V_{CC_A})/8
4 x (V_{CC_A})/8
5 x (V_{CC_A})/8
6 x (V_{CC_A})/8
7 x (V_{CC_A})/8
V_{CC_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
(0V), OP_CTL is forced LOW (0V). The input level at which the part is muted can be set
by the SQ_ADJ pin through suitable voltage variances as described in Section 4.4.
NOTE: When SQ_ADJ functionality is used and/or in Auto_mute, the SLEEP pin should
be left open.
GS2993 Dual Output Adaptive Cable Equalizer
Data Sheet
53966 - 4
August 2012
16 of 23
Propietary & Confidential