GS2993 Dual Output Adaptive Cable Equalizer

Data Sheet

53966 - 4

August 2012

16 of 23

Propietary & Confidential

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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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:

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.

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.

Table 4-5: OP1_CTL and OP2_CTL Functions and Levels

Level

Swing

De-emphasis

Mute

Voltage

0

800mV

Off

N

0

1

800mV

2dB

N

2

800mV

4dB

N

3

800mV

6dB

N

4

400mV

Off

N

5

400mV

2dB

N

6

400mV

4dB

N

7

400mV

6dB

N

8

400mV

N/A

Y