LMH0056_07 Datasheet, PDF (13/16 Pages) National Semiconductor (TI) – HD/SD SDI Reclocker with 4:1 Input Multiplexer

SCO_EN
Input SCO_EN enables the SCO/SDO2 differential output to
function either as a serial data-rate clock or second serial data
output. SCO/SDO2 functions as a serial data-rate clock when
SCO_EN is high. This pin has an internal pull-down device.
The default state (low) enables the SCO/SDO2 output as a
second serial data output.
CRYSTAL OR EXTERNAL CLOCK REFERENCE
The LMH0056 uses a 27 MHz crystal or external clock signal
as a timing reference input. A 27 MHz parallel resonant crystal
and load network may be connected to the XTAL IN/EXT CLK
and XTAL OUT pins. Alternatively, a 27 MHz LVCMOS com-
patible clock signal may be input to XTAL IN/EXT CLK. Pa-
rameters for a suitable crystal are given in Table 4.
TABLE 4. Crystal Parameters
Parameter
Value
Frequency
27 MHz
Frequency Stability
±50 ppm @ recommended
drive level
Parameter
Operating Mode
Load Capacitance
Shunt Capacitance
Series Resistance
Recommended Drive Level
Maximum Drive Level
Operating Temperature
Range
Value
Fundamental mode, Parallel
Resonant
20 pF
7 pF
40Ω max.
100 µW
500 µW
−10°C to +60°C
13
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