LVDSEVAL-001 National Semiconductor, LVDSEVAL-001 Datasheet - Page 9

• Manufacturer Part Number: LVDSEVAL-001
• Description: EVALUATION BOARD FOR DS90LV031A
• Manufacturer: National Semiconductor

Specifications of LVDSEVAL-001

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *LVDSEVAL-001

A1 - B1
Figure 7: LVDS differential waveform measured with TEK P6135A probes and 602 scope
6.1.7 Demo PCB Options
Option 1: 450 Ohm Resistors
A provision for a series 450 Ohm resistor (RS1-4) is provided on the receiver output signal. By cutting
the trace between the “RS” pads and installing a 450 Ohm resistor a standard 50 Ohm scope probe may
be used (500 Ohm total load). Note that the signal is divided down (1/10) at the scope input.
Option 2: Disabling the LVDS Driver
The quad driver features a ganged enable. An active high or an active low input are provided. On the evalu-
ation PCB the active high input has been hard wired to ground (-, off). The active low input (EN*) is routed
to a jumper (J1). The jumper provides a connection to the Vcc plane (+) or to the Ground plane (-). To
enable the driver connect the jumper to ground, to disable the driver connect the jumper to the power plane.
Option 3: Disabling the LVDS Receiver
The quad receiver features a ganged enable (same as the driver). An active high or an active low are
provided. On the evaluation PCB the active high input has been hard wired to ground (-, off). The active
low input (EN*) is routed to a jumper (J2). The jumper provides a connection to the Vcc plane (+) or to
the Ground plane (-). To enable the receiver connect the jumper to ground, to disable the receiver
connect the jumper to the power plane.
Option 4: Cables
Different cables may also be tested (different lengths, materials, constructions). A standard SCSI-2 50-pin
connector/pinout has been used (J3 and J4). Simply plug in a SCSI-2 cable or build a custom cable.
Option 5: Power Supply /Components (C/LV/422)
The LVDS quads are offered in an industry standard pinout made popular by the 26LS31/2 quad 5V RS-422
devices. This standard pinout allows different devices (and power supplies) to be substituted and evaluated.
The following National Semiconductor devices may be tested (U1/U2):
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