SP508E Datasheet, PDF (1/29 Pages) Exar Corporation – Rugged 20Mbps, 8 Channel Multi-Protocol Transceiver with Programmable DCE/DTE and Termination Resistors

SP508E
Rugged 20Mbps, 8 Channel Multi-Protocol Transceiver
with Programmable DCE/DTE and Termination Resistors
FEATURES
• 20Mbps Differential
Transmission
Rates ^Now
Available
in
Lead
Free
Packaging
• 15kV ESD Tolerance for Analog I/Os
Refer to page 7 for pinout
• Internal Transceiver Termination Resistors
for V.11/V.35
• Interface Modes:
– RS-232 (V.28)
– X.21 (V.11)
– RS-449/V.36
(V.10 & V.11)
– EIA-530 (V.10 & V.11)
– EIA-530A (V.10 & V.11)
– V.35
• Software Selectable Protocols with 3-Bit Word
• Eight Drivers and Eight Receivers
• V.35/V.11 Receiver Termination Network
Disable Option
• Easy Flow-Through Pinout
• +5V Only Operation
• Individual Driver/Receiver Enable/Disable Controls
• Operates in DTE or DCE Mode
APPLICATIONS
• Router
• Frame Relay
• CSU
• DSU
• Internal Line or Digital Loopback Testing
• PBX
• Adheres to NET1/NET2 and TBR-2 Requirements ^{• Secure Communication Terminals}
DESCRIPTION
The SP508E is a monolithic device that supports eight (8) popular serial interface standards
for Wide Area Network (WAN) connectivity. The SP508E is fabricated using a low power
BiCMOS process technology, and incorporates an Exar regulated charge pump allowing +5V
only operation.Exar's patented charge pump provides a regulated output of +5.8V, which
will provide enough voltage for compliant operation in all modes. Eight (8) drivers and eight
(8) receivers can be configured via software for any of the above interface modes at any
time. The SP508E requires no additional external components for compliant operation for
all of the eight (8) modes of operation other than four capacitors used for the internal charge
pump. All necessary termination is integrated within the SP508E and is switchable when
V.35 drivers and V.35 receivers, or when V.11 receivers are used. The SP508E provides the
controls and transceiver availability for operating as either a DTE or DCE.
Additional features with the SP508E include internal loopback that can be initiated in any
of the operating modes by use of the LOOPBACK pin. While in loopback mode, receiver
outputs are internally connected to driver inputs creating an internal signal path bypassing
the serial communications controller for diagnostic testing. The SP508E also includes a latch
enable pin with the driver and receiver address decoder. The internal V.11 or V.35 receiver
termination can be switched off using a control pin (TERM_OFF) for monitoring applications.
All eight (8) drivers and receivers in the SP508E include separate enable pins for added
convenience. The SP508E is ideal for WAN serial ports in networking equipment such as
routers, access concentrators, network muxes, DSU/CSU's, networking test equipment, and
other access devices.
Applicable U.S. Patents-5,306,954; and others patents pending
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.comSP508E_100_072412