Figure 3-1: Output Optimized for Waveform Symmetry, L=8.2nH, R=75Ω
(Typical ORL=13.5dB)
Figure 3-2: Output Optimized for Return Loss, L=12nH, C=0.5pF, R=75Ω
(Typical ORL=18dB)
Figure 3-1 and Figure 3-2 show the eye diagram of the GS1508 output for two different
output compensation conditions.
Figure 3-2 shows the GS1508 output optimized for wideband return loss of 18dB.
Figure 3-1 shows the GS1508 output optimized for output waveform symmetry. In this
case, the output may not exhibit a return loss of 15dB.
When measuring return loss at the GS1508 output, it is necessary to take the
measurement for both a logic HIGH and a logic LOW output condition. This is because
the output protection diodes act as varactors (voltage controlled capacitor), as shown in
Figure 3-3.
Consequently, the output capacitance of the GS1508 is dependent on the logic state of
the output.
GS1508 HD-LINX™ HDTV Cable Driver
Data Sheet
6 of 14
9500 - 6
August 2010
GENNUM [ GENNUM CORPORATION ]
