SP211EH Datasheet, PDF (5/16 Pages) Exar Corporation – High Speed +5V High Performance

features
As in the original RS-232 multi-channel
products, the SP211EH and SP213EH high
speed multi–channel RS-232 line transceiv-
ers provide a variety of configurations to fit
most designs, especially high speed appli-
cations where +/-12V is not available. The
SP211EH/213EH is a superior high speed
drop-in replacement to our previous versions
as well as popular industry standards.
All devices in this series feature low–power
CMOS construction and Exar's–proprietary
on-board charge pump circuitry to generate
the RS-232 signal voltages. The ability to
use 0.1µF charge pump capacitors saves
board space and reduces production costs.
The devices in this series provide different
driver/receiver combinations to match any
application requirement.
The SP211EH and SP213EH models feature
a low–power shutdown mode, which reduces
power supply drain to 1µA. The SP213EH
includes a Wake-Up function which keeps
two receivers active in the shutdown mode,
unless disabled by the EN pin.
The family is available in 28 SOIC (wide)
and SSOP (shrink) small outline packages.
Devices can be specified for commercial (0˚C
to +70˚C) and industrial/extended (–40˚C to
+85˚C) operating temperatures.
Theory of Operation
The SP211EH and SP213EH devic-
es are made up of three basic cir-
cuit blocks — 1) transmitter/driver,
2) receiver and 3) the EXAR–proprietary
charge pump. Each model within the series
incorporates variations of these circuits to
achieve the desired configuration and per-
formance.
Transmitter/Drivers
The drivers of this series can maintain a
typical data rate of 500kbps.
This superior RS-232 data transmission
rate makes the SP211EH/213EH series an
ideal match for many designs in personal
computer peripherals and LAN applications
that demand high speed performance.
The drivers are inverting transmitters, which
accept either TTL or CMOS inputs and output
the RS-232 signals with an inverted sense
relative to the input logic levels. Typically, the
RS-232 output voltage swing is +/-9V with
no load, and +/-5V minimum with full load.
The transmitter outputs are protected against
infinite short–circuits to ground without
degradation in reliability. The drivers of the
SP211EH, and SP213EH can be tri–stated
by using the SHUTDOWN function.
In the "power-off" state, the output imped-
ance will remain greater than 300 ohms,
again satisfying the RS-232 specifications.
Should the input of the driver be left open,
an internal 400k ohm pull-up resistor to VCC
forces the input high, thus committing the
output to a low state. The slew rate of the
transmitter output is internally limited to a
maximum of 30V/µs in order to meet the
EIA/RS-232 and ITU V.28 standards.The
transition of the output from high to low also
meets the monotonicity requirements of the
standard.
Receivers
The high performance receivers of the
SP211EH/213EH devices can accept input
signals at a typical data rate or 500kbps. The
receivers convert RS-232 level input signals
to inverted TTL level signals. Since the input
is usually from a transmission line where long
cable lengths and system interference can
degrade the signal, the inputs have a typical
hysteresis margin of 500mV. This ensures
that the receiver is virtually immune to noisy
transmission lines. Should an input be left
unconnected, a 5kΩ pull-down resistor to
ground will commit the output of the receiver
to a high state.
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com

SP211EH_213EH_101_060111