SP207ET-L/TR Exar Corporation, SP207ET-L/TR Datasheet - Page 6
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SP207ET-L/TR
Manufacturer Part Number
SP207ET-L/TR
Description
5V +/-15KV ESD, 5 Driver / 3 Receiver RS-232
Manufacturer
Exar Corporation
Type
Transceiverr
Datasheet
1.SP211CA-LTR.pdf
(14 pages)
Specifications of SP207ET-L/TR
Number Of Drivers/receivers
5/3
Protocol
RS232
Voltage - Supply
4.5 V ~ 5.5 V
Mounting Type
Surface Mount
Package / Case
24-SOIC (0.300", 7.50mm Width)
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
TRANSMITTER/DRIVER
The drivers are inverting transmitters, which ac-
cept either TTL or CMOS inputs and output the
RS-232 output 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 infi-
nite short-circuits to ground without degrada-
tion in reliability. The drivers of the SP206 and
SP2 can be tri-stated by using the SHUT-
DOWN function.
In the "power off" state, the output impedance
will remain greater than 300 Ohms, again satis-
fying the RS-232 specifications. Should the input
of the driver be left open, an internal 400kOhm
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 he EIA
standards (EIA RS-232D 2,,7, Paragraph 5).
The transition of the loaded output from high to
low also meets the monotonicity requirements
of the standard.
Figure . Charge Pump Waveforms
Figure 2, Charge pump - Phase
a) C2+
b) C2+
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)668-7000 • Fax (50)668-707 • www.exar.com SP206, 207, 208, 2_00_0760
+0V
-0V
GND
GND
C
1
–5V
+
–
V
CC
= +5V
C
6
2
+5V
–5V
+
–
RECEIVERS
The receivers convert RS-232 input signals to
inverted TTL signals. Since the input is usu-
ally from a transmission line where long cable
length and system interference can degrade
the signal, the inputs have a typical hysteresis
margin of 500mV. This ensures that the re-
ceiver is virtually immune to noisy transmission
lines. Should an input be left unconnected, an
internal 5kohm pull-down resistor to ground will
commit the output of the receiver to a HIGH
state.
SHUTDOWN MODE
The SP206 and SP2 feature a control input
(SD) which will disable the device and reduce
the power supply current to less than 0µA,
making the parts ideal for battery-powered sys-
tems. In the "shutdown" mode the receivers
and transmitters will both be tri-stated. The V+
output of the charge pump will discharge to Vcc
and the V- output will discharge to ground.
ENAblE (EN)
The SP206 and SP2 feature an enable input
which allows the receiver outputs to be either
tri-stated or enabled. This can be especially
useful when the receiver is tied directly to a
microprocessor data bus. The enable pin is
active high.
+
–
C
C
4
3
+
–
V
V
DD
SS
Storage Capacitor
Storage Capacitor
DESCRIPTION