SD356EVK National Semiconductor, SD356EVK Datasheet - Page 13
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SD356EVK
Manufacturer Part Number
SD356EVK
Description
LMH0356 3 Gbps HD/SD SDI Reclocker with 4:1 Input Mux and FR4 EQs
Manufacturer
National Semiconductor
Datasheet
1.SD356EVK.pdf
(18 pages)
SCO_EN
Input SCO_EN enables the SCO/SDO2 differential output to
function either as a serial clock or second serial data output.
SCO/SDO2 functions as a serial 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.
ENABLE
The ENABLE pin is used to enable or disable the LMH0356.
When the device is disabled, the output drivers and most of
the internal circuitry are powered down. The crystal oscillator /
external clock reference circuitry (XTAL IN and XTAL OUT)
remain active regardless of the state of ENABLE, allowing the
27 MHz reference clock signal to be generated and passed
on to additional reclockers. The ENABLE pin is active high
and has an internal pull-up device to enable the LMH0356 by
default.
CRYSTAL OR EXTERNAL CLOCK REFERENCE
The LMH0356 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
13
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
Frequency
Frequency Stability
Operating Mode
Load Capacitance
Shunt Capacitance
Series Resistance
Recommended Drive Level
Maximum Drive Level
Operating Temperature
Range
Parameter
TABLE 4. Crystal Parameters
27 MHz
±50 ppm @ recommended
drive level
Fundamental mode, Parallel
Resonant
20 pF
7 pF
40Ω max.
100 µW
500 µW
−10°C to +60°C
Value
Table
www.national.com
4.