EB-GS2993
Evaluation Board User Guide
55092 - 0
April 2010
6 of 10
1.5 Potentiometer Settings
Adjusting the potentiometers clockwise will decrease the voltage level at the SQ_ADJ
and OP_CTL pins. Adjusting the potentiometers counter-clockwise will increase the
voltage level at the SQ_ADJ and OP_CTL pins.
1.5.1 OP1_CTL, OP2_CTL Potentiometer Settings
The output control potentiometer settings are described in
Table 1-5
below:
1.5.2 Squelch Adjust (SQ_ADJ) Potentiometer Settings
There is one multi-turn potentiometer on the EB-GS2993 assigned for squelch adjust,
which adjusts the voltage seen at the SQ_ADJ pin. This input adjusts the threshold of the
CD pin. When the SQ_ADJ input is 0V, all cable lengths will be equalized. When the
SQ_ADJ input is 3.3V, there will be no equalization regardless of the cable length. Please
refer to the GS2993 Data Sheet for more details on carrier detect and squelch adjust.
Table 1-4: LED_EN (JP10) Jumper Settings
Label
Connection
Description
C
onnected (default)
LED is enabled
Unconnected
LED is disabled
Table 1-5: OP1_CTL, OP2_CTL Input Settings
Level
Swing
De-emphasis
Mute
Voltage
0
800mV
Off
N
0
1
800mV
2dB
N
1 x (V
CC
/8)
2
800mV
4dB
N
2 x (V
CC
/8)
3
800mV
6
dB
N
3 x (V
CC
/8)
4
400mV
Off
N
4 x (V
CC
/8)
5
400mV
2dB
N
5 x (V
CC
/8)
6
400mV
4dB
N
6
x (V
CC
/8)
7
400mV
6
dB
N
7 x (V
CC
/8)
8
400mV
N/A
Y
V
CC
