SD356EVK/NOPB National Semiconductor, SD356EVK/NOPB Datasheet - Page 3

• Manufacturer Part Number: SD356EVK/NOPB
• Description: EVAL BOARD FOR LMH0356
• Manufacturer: National Semiconductor

Specifications of SD356EVK/NOPB

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The SDI input and output connectors occur in pairs as the inputs and outputs of the LMH0356 SDI
reclocker are differential. It is not necessary to terminate unused inputs. Both the inputs and outputs of
the LMH0356 SDI reclocker are internally terminated.
The SD356EVK has two sets of outputs connected to the two outputs of the LMH0356 SDI reclocker.
The first set of outputs, labeled SDO, always carry the digital video data signal unless they are muted. If
the reclocker is locked and not bypassed, these outputs carry a reclocked version of the input signal. If
the reclocker is unlocked or bypassed, these outputs carry an unmodified replica of the input signal. The
outputs may be muted by the output mute control described in a later section.
The second set of outputs of the SD356EVK, labeled SCO/SDO2, can be set either to output a copy of
the data on the first set of outputs, either reclocked or not as describe above, or to output the recovered
clock signal from the LMH0356 SDI reclocker. The clock signal is only available when the LMH0356 SDI
reclocker is locked to a valid input signal.
The inputs and outputs of the SD356EVK PC board are AC-coupled with 1 µF 0402-size coupling
capacitors. These capacitors are rated for 10 VDC working voltage. The inputs and outputs of the
SD356EVK board may be terminated in any DC voltage that does not exceed this 10 V limit relative to the
negative power supply. The coupling capacitors may be replaced with 0402-size 0Ω resistors for DC-
coupled evaluation.
FR-4 Traces
Two of the inputs to the SD356EVK, inputs SDI0 and SDI1, are equipped with long FR-4 test traces. The
trace lengths are 30 inches and 15 inches respectively on the two inputs. The other two inputs are
coupled to the LMH0356 SDI reclocker through very short FR-4 traces. The FR-4 test traces are meant
to demonstrate the action of the input passive equalizers. The input passive equalizers compensate for
the ISI introduced by long PC board traces. The SD356EVK demonstrates that the performance of the
LMH0356 SDI reclocker is unaffected by up to 30 inches of lossy FR-4 trace on its inputs.
The SD356EVK also includes a 30 inch FR-4 test trace which can be used to evaluate the ISI effect
introduced by such a trace. If desired, connectors can be soldered on to this test trace and the ISI can be
measured by external test equipment. If this is desired, the same connectors used on the inputs and
outputs of the SD356EVK may be used. These connectors are specified in the bill of materials for the
SD356EVK.
DC Power Connectors
DC power is applied to the SD356EVK by means of standard .175-inch diameter binding posts. Three
power supply terminals are provided. The first is a common ground, to which the negative supply voltage
should be connected. This is the black binding post on the board. The two red binding posts on the
board are meant to provide 3.3 VDC to 1) the LMH0356 SDI reclocker alone, and 2) the remainder of the
circuitry on the SD356EVK board. The dual-supply configuration permits measurement of the current
drawn by the LMH0356 SDI reclocker independent of the other devices on the board if desired. The two
supplies may be connected together if desired using either an external jumper or the onboard header
between the 3.3 V power supply terminals.
The power supply is not regulated on the SD356EVK board so the effects of power supply variations can
be evaluated. It is recommended that the maximum supply voltage rating of the LMH0356 (4 VDC) not
be exceeded.
The LMH0356 SDI reclocker can be powered-down using its enable feature. This feature is accessible
through the control inputs described in the next section. The dual-supply configuration of the SD356EVK
can be used to observe the effect on supply current of powering down the LMH0356.
Controls and Indicators
The control lines of the LMH0356 SDI reclocker can be controlled by various means using the SD356EVK.
The primary method for controlling these lines is the DIP switches located on the SD356EVK board. The
DIP switches are labeled according to their function. When the switch actuator is pushed to the right
SD356EVK User Manual
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Rev 1.0
© 2008, National Semiconductor Corp.