SP509 Datasheet, PDF (20/29 Pages) Sipex Corporation – Rugged 40Mbps, 8 Channel Multi-Protocol Transceiver with Programmable DCE/DTE and Termination Resistors

The SP509 contains highly integrated serial
transceivers that offer programmability between
interface modes through software control. The
SP509 offers the hardware interface modes for
RS-232 (V.28), RS-449/V.36 (V.11 and V.10),
EIA-530 (V.11 and V.10), EIA-530A (V.11 and
V.10), V.35 (V.35 and V.28) and X.21(V.11). The
interface mode selection is done via three control
pins, which can be latched via microprocessor
control.
The SP509 has eight drivers, eight receivers, and
Sipex's patented on-board charge pump (5,306,954)
that is ideally suited for wide area network
connectivity and other multi-protocol applications.
Other features include digital and line loopback
modes, individual enable/disable control lines for
each driver and receiver, fail-safe when inputs are
either open or shorted, individual termination
resistor ground paths, separate driver and receiver
ground outputs, enhanced ESD protection on driver
outputs and receiver inputs.
THEORY OF OPERATION
The SP509 device is made up of 1) the drivers, 2)
the receivers, 3) a charge pump, 4) DTE/DCE
switching algorithm, and 5) control logic.
Drivers
The SP509 has eight enhanced independent drivers.
Control for the mode selection is done via a three-
bit control word into D0, D1, and D2. The drivers
are prearranged such that for each mode of
operation, the relative position and functionality
of the drivers are set up to accommodate the
selected interface mode. As the mode of the drivers
is changed, the electrical characteristics will change
to support the required signal levels. The mode of
each driver in the different interface modes that
can be selected is shown in Table 1.
FEATURES
There are four basic types of driver circuits –
ITU-T-V.28 (RS-232), ITU-T-V.10 (RS-423),
ITU-T-V.11 (RS-422), and CCITT-V.35.
The V.28 (RS-232) drivers output single-ended
signals with a minimum of +5V (with 3kΩ &
2500pF loading), and can operate over 120kbps.
Since the SP509 uses a charge pump to generate
the RS-232 output rails, the driver outputs will
never exceed +10V. The V.28 driver architecture
is similar to Sipex's standard line of RS-232
transceivers.
The RS-423 (V.10) drivers are also single-ended
signals which produce open circuit V_OL and V_OH
measurements of +4.0V to +6.0V. When terminated
with a 450Ω load to ground, the driver output will
not deviate more than 10% of the open circuit
value. This is in compliance of the ITU V.10
specification. The V.10 (RS-423) drivers are used
in RS-449/V.36, EIA-530, and EIA-530A modes
as Category II signals from each of their
corresponding specifications. The V.10 drivers
are guaranteed to transmit over 120kbps, but can
operate at over 1Mbps if necessary.
The third type of drivers are V.11 (RS-422)
differential drivers. Due to the nature of differential
signaling, the drivers are more immune to noise as
opposed to single-ended transmission methods.
The advantage is evident over high speeds and
long transmission lines. The strength of the driver
outputs can produce differential signals that can
maintain +2V differential output levels with a load
of 100Ω. The signal levels and drive capability of
these drivers allow the drivers to also support
RS-485 requirements of +1.5V differential output
levels with a 54Ω load. The strength allows the
SP509 differential driver to drive over long cable
lengths with minimal signal degradation. The V.11
drivers are used in RS-449, EIA-530, EIA-530A
and V.36 modes as Category I signals which are
used for clock and data. Sipex's new driver design
over its predecessors allow the SP509 to operate
over 40Mbps for differential transmission.
Date: 8/19/04
SP509 Enhanced WAN Multi–Protocol Serial Transceiver
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© Copyright 2004 Sipex Corporation