GS9024 Data Sheet
5.5 I/O Description
5.5.1 High Speed Analog Inputs (SDI/SDI)
SDI/SDI are high impedance inputs which accept differential or single-ended input
drive.
Figure shows the recommended interface when a single-ended serial digital signal
is used.
10nF
SDI
75Ω
GS9024
75Ω
10nF
SDI
37.5Ω 75Ω
5.5.2 High Speed Outputs (SDO/SDO)
SDO/SDO are current mode outputs that require external pullups (see Figure ).
The output signal swings are 800mV when 75Ω resistors are used. A diode can be
placed between V and the pullups to shift the signal levels down by
CC
approximately 0.7 volts. When the output traces are longer than 1 inch, controlled
impedance traces should be used. The pullup resistors should be placed at the end
of the output traces as they terminate the trace in its characteristic impedance
(75Ω).
V
CC
75Ω
75Ω
SDO
SDO
GS9024
521-70-10 February 2005
13 of 16
GENNUM [ GENNUM CORPORATION ]
