Texas Instruments SN65LVDS386EVM, Руководство пользователя

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Pattern Generator
3-2
3.1 Pattern Generator
The SN65LVDS387 EVM requires a signal or pattern generator that can pro-
vide at least one LVTTL input signal to the device. The LVTTL signal levels pro-
vided to the SN65LVDS387EVM must have a V
IH
= 2 Vdc minimum. Sixteen
simultaneous LVTTL inputs are required to fully exercise the device, so a pat-
tern generator with 16 parallel LVTTL outputs and a signaling-rate range up
to several hundred megabits-per-second (Mbps) is suggested. The Tektronix
HFS-series of pattern generators, or equivalent, can be used to provide the
LVTTL inputs signals. HFS-9DG1 plug-in cards are recommended as they can
be used to provide both single-ended inputs for the SN65LVDS387 driver and
differential inputs for the SN65LVDS386 receiver.
3.2 Oscilloscope and Scope Probes
The signaling rates and LVDS signal transitions are very fast (less than 1 nS).
To adequately monitor these signals will require an oscilloscope with a mini-
mum bandwidth of 1 GHz. The probes need to have a similar bandwidth to pre-
vent significant measurement errors. A Tektronix 784C oscilloscope with
P6243 or P6245 single-ended probes, and P6247 differential probes, or equiv-
alent, is suggested.
3.3 Power Supply
A single-output dc power supply is required to provide Vcc and Gnd to the
EVM. This supply is connected to J1 (Vcc) and J2 (GND) on the EVM. An ad-
justable dc range of 2–4 Vdc and a current of 200 mA dc is required. When
testing both the SN65LVDS387EVM and SN65LVDS386EVM together as a
system, either a single 500-mA dc-supply can be used, or two separate power
supplies may be used so performance with different Vcc levels on each EVM
may be evaluated.
3.4 Cables
There are no cables provided with either the SN65LVDS387EVM or the
SN65LVDS386EVM. When evaluating either the SN65LVDS387EVM or
SN65LVDS386EVM separately, the only cables required are those connecting
the input signal source to the input of the EVM. When connecting the
SN65LVDS387EVM to the SN65LVDS386EVM to perform system tests, users
may evaluate system performance using different types and lengths of
cabling. This is done by inserting the bare conductor into the LVDS connectors
between the two EVMs (the conductors have to be exposed by removing
approximately 1 to 1.5 centimeters of insulation from each conductor). It is
recommended to select a cable with a characteristic impedance (Zo) of
100
Ω
(
±
10%). Any cable which meets the requirements of EIA-568A Category
5 (CAT5) is recommended.