SP504 Sipex, SP504 Datasheet - Page 17

• Manufacturer Part Number: SP504
• Description: WAN Multi-Mode Serial Transceiver
• Manufacturer: Sipex

tory for more information). The drivers are
controlled with the data bits labeled TDEC
–
3
TDEC
. All of the drivers can be put into tri-
0
state mode by writing 0000 to the driver decode
switch. The three drivers TxD, ST and TxC,
have a 150Ω pull-down resistor to ground con-
nected at the (b) output. This resistor is part of
the V.35 driver circuitry and should be con-
nected when in V.35 mode. Tri-state is possible
for all drivers in RS-232 mode. The receivers
are controlled with data bits RDEC
–RDEC
;
3
0
the code 0000 written to the receivers will place
the outputs into tri-state mode. The 0000 de-
coder word will override the enable control line
for the one receiver (SCT).
Using the V.35_STAT Pin
The SP504 includes a V.35 status pin where the
V35_STAT pin (pin 18) is a logic HIGH ("1")
when the decoder is set to V.35 mode. The pin
is a logic LOW ("0") when in all other modes
including tri-state (decoder set at "0000"). Pin
18 allows the user to easily add FET switches or
solid state relays to connect the external 150Ω
resistor for V.35 operation. V35_STAT can be
connected to the gate of the FET switches or the
control of the relays so that the 150Ω resistors
are connected to the non-inverting output of the
three V.35 drivers. The output current of the
V35_STAT pin is that of a typical TTL load of
–3.2mA. The electrical specifications are simi-
lar to the SP504 receiver outputs. This feature
would reduce additional logic required by older
traditional methods.
NET1/NET2 Testing and Compliancy
Many system designers are required to certify
their system for use in the European public
network. Electrical testing is performed in ad-
herence to the NET (Norme Européenne de
Télécommunication) which specifies the ITU
Series V specifications. The SP504 adheres to
all the required physical layer testing for NET1
and NET2. Consult factory for details.
Rev: A Date:1/27/04
SP504 Multi–Mode Serial Transceivers
© Copyright 2004 Sipex Corporation
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