GS3490 Datasheet, PDF (15/22 Pages) Semtech Corporation – Configurable Adaptive Cable Equalizer/Cable Driver

Table 4-2: Typical Common Mode Output Voltage Levels (V_CMDDO) - VCC = 3.3V
Output Voltage Swing
(ΔV_DDO)
425mV_ppd
850mV_ppd
Termination Type 1
(See Figure 4-1)
3.09V
2.88V
Termination Type 2
(See Figure 4-2)
3.19V
3.09V
GS3490 _VCC
50Ω
50Ω
DDO
50Ω
DDO
50Ω
100Ω
GS3490 _VCC
VCC VCC
50Ω
50Ω
50Ω 50Ω
DDO
50Ω
DDO
50Ω
Figure 4-1: 100Ω Parallel Output Termination
Figure 4-2: 50Ω Termination to VCC
4.1.7 Adjustable Output Swing, De-Emphasis and Mute (EQ_OP_CTL)
The EQ_OP_CTL input pin determines the output swing and De-emphasis settings for
DDO/DDO.
The EQ_OP_CTL pin is an analog input allowing different combinations of output swing,
De-emphasis and mute. The possible values are listed in Table 4-3 below:
Table 4-3: EQ_OP_CTL Functions and Levels
Level
0
1
2
3
4
5
6
7
8
Swing (mV_ppd) De-emphasis
850
Off
850
2dB
850
4dB
850
6dB
425
Off
425
2dB
425
4dB
425
6dB
425
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
GS3490
Final Data Sheet
GENDOC-058568
Rev. 1
April 2014
www.semtech.com
15 of 22
Proprietary & Confidential