SP504EB Datasheet, PDF (3/18 Pages) Sipex Corporation – Evaluation Board Manual

Fuse
At the upper right-hand side of the board, just
below the DB-25 connector, is a location for a
fuse. There must either be a fuse, a low value
resistor (1 to 10 ohms) or a jumper wire installed
at this location. A one amp fuse is recommended.
V35_STAT
As mentioned previously, the SP504 device has
a TTL output labled V35_STAT. When the
SP504 is configured to V.35 mode, this pin
provides a high level TTL output. In all other
modes, this pin provides a low level TTL output.
The V35_STAT output is used to control FET
switches which switch 150 ohm V.35 termina-
tion resistors in or out of the SP504 circuit
configuration. This feature is labeled on the
SP50x Evaluation Board but is not used. The
rocker switch for V35_STAT must be in the OFF
position (rocker down) when using SP504 board.
USING THE EVALUATION BOARD
On the bottom righ-hand side of the evaluation
board are two pins identified as GND and V_CC.
Connect this GND to the power supply ground.
Connect V to a +5 volt DC power supply.
CC
If possible, limit the supply current to 0.5-1.0
Amp. Do not switch power on when connecting
power to the evaluation board.
All Drivers Active with Single TTL input
SP504
On the right-hand side of the evaluation board,
connect jumper wires between all seven driver
inputs (TxC, TxD, DTR, RTS, LL, RL, and ST)
to each of the corresponding TTL pin on the right
hand side. Next, configure the mode selection to
the desired mode using TDEC3-TDEC0 on the
right-hand DIP switch and RDEC3-RDEC0 on
the left-hand DIP switch if the SP504 is used.
Connect a system clock or signal generator with
a TTL-level output and a frequency within the
acceptable range of the driver under test to any of
the TTL pins. The common bus will route the
signal to each driver with a jumper installed to
the TTL bus. Ensure that /STEN and /TTEN
enable switches on the left-hand DIP switch
have been set to low position (rocker down) to
enable the drivers. Once the power is on and the
driver inputs receive a signal, the driver outputs
can be analyzed with a oscilloscope or digital
multi-meter. The mode selection can be
performed at any time using the TDEC and
RDEC positions on the DIP switches.
SP505
This is similar to the SP505 except that the
RDEC positions on the left DIP switch are now
low-active enable lines for the ST, DTR, RTS,
and LL drivers. The V35_STAT is now the low-
active RL driver enable pin.
DRIVER/RECEIVER LOOPBACK
SP504
This example uses the ST driver looped back into
the SCT receiver. First, configure the mode
select for the desired mode using RDEC3-RDEC0
on the left-hand DIP switch and TDEC3-TDEC0
on the right-hand DIP switch. Connect a jumper
wire between an ST(a) pin and an SCT(a) pin.
If your mode select is for a differential driver/
receiver, then also connect a jumper wire be-
tween an ST(b) pin and an SCT(b) pin. Next,
connect a signal generator to the ST pin.
The signal generator output must be a TTL-level
output at a frequency within the acceptable range
of the driver mode under test. Set /STEN to logic
low (rocker down) and SCTEN to logic high
(rocker up). The driver outputs are connected
back to the receiver inputs so that driver input to
receiver output delays can be examined. This
configuration is similar for the other drivers.
SP505
The same approach for the SP504 above can be
applied for the SP505. However, the SP505 can
be programmed internally for loopback. DEC₀
to DEC₃ should be configured as "1010", respec-
tively for a single ended loopback. DEC₀ to
DEC₃ should be configured as "1011", respec-
tively for a differential loopback.
504/505AppNote/03
New SP504/505 Evaluation Board
3
© Copyright 2000 Sipex Corporation