SP202E,SP232E, SP233E, SP310E and SP312E
High Performance RS-232 Line Drivers/Receivers
FEATURES
• Operates from a Single +5V Power Supply
• Meets all RS-232D and ITU V.28 Specifications
• Operates with 0.μF to 0μF Ceramic Capacitors
• No External Capacitors required (SP233E)
• Low Power Shutdown (SP30E, SP32E)
• High Data Rate - 20kbps under load
• Low power CMOS Operation
• Lead Free packaging available
• Improved ESD Specifications:
+/-5kV Human Body Model
The SP202E, SP232E, SP233E, SP30E and SP32E devices are a family of line driver and re-
ceiver pairs that meets the specifications of RS-232 and V.28 serial protocols. The devices are pin-
to-pin compatible with Exar's SP232A, SP233A, SP30A and SP32A devices as well as popular
industry standard pinouts. The ESD tolerance has been improved on these devices to over +/-5kV
for Human Body Model. This series offer a 20kbps data rate under load, small ceramic type 0.μF
charge pump capacitors and overall ruggedness for comercial applications. Features include Exar's
BiCMOS design which allowing low power operation without sacrificing performance. The series is
available in lead free packages with commercial and industrial temperature ranges.
DESCRIPTION
SELECTION TABLE
Model
Number of RS-232
Drivers
Receivers
No. of RX
active in
Shutdown
No. of External
0.
μ
F Capacitors
Shutdown
WakeUp
TTL Tri-State
SP202E
SP232E
SP233E
SP30E
SP32E
2
2
2
2
2
2
2
2
2
2
0
0
0
0
2
4
4
0
4
4
No
No
No
Yes
Yes
No
No
No
No
Yes
No
No
No
Yes
Yes
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)668-7000 • www.exar.com SP202E,232E,233E, 30E, 32E_00_0608
This is a stress rating only and functional operation of
the device at these ratings or any other above those
indicated in the operation section of the specification
is not implied. Exposure to absolute maximum ratings
conditions for extended periods of time may affect re-
liability.
Supply Voltage (V
CC
)....................................................+ 6V
V+........................................................................... (Vcc-0.3V) to +.0V
V- .............................................................................-.0V
Input Voltages
Tin.....................................................-0.3V to (Vcc + 0.3V)
Rin............................................................................+/-5V
Output Voltages
Tout...............................................(V+, +0.3V) to (V-, -0.3V
Rout...................................................-0.3V to (Vcc + 0.3V)
AbSoLUTE MAxiMUM RATingS
Short Circuit duration
Tout.....................................................Continuous
Package Power Dissipation:
Plastic DIP...............................................375mW
(derate 7mW/°C above +70°C)
Small Outline...........................................375mW
(derate 7mW/°C above +70°C)
Storage Temperature..................-65°C to +50°C
Vcc = 5V ±0%, 0.
μ
F charge pump capacitors, T
min
to T
max
, unless otherwise noted, Typical values are Vcc =
5V and T
a
=25°C
PARAMETER
TTL inPUT
Logic Threshold LOW
Logic Threshold HIGH
Logic Pull-Up Current
TTL oUTPUT
Output Voltge LOW
Output Voltage HIGH
Leakage Current **;
T
a
= +25°C
RS-232 oUTPUT
Output Voltage Swing
Output Resistance
Output Short Circuit Current
Maximum Data Rate
RS-232 inPUT
Voltage Range
Voltage Threshold LOW
Voltage Threshold HIGH
Hysteresis
Resistance
** SP30E and SP32E only
ELECTRiCAL CHARACTERiSTiCS
Min
TYP
MAx
UniT
TEST ConDiTionS
T
in
, En, SD, On/OFF
T
in
, En, SD, On/OFF
T
in
= 0V
i
OuT
= 3.2ma: V
cc
= +5V
i
OuT
= -1.0ma
En = V
cc
,
0V ≤ V
OuT
≤ Vcc
3.5
0.05
2.0
5
0.8
Volts
Volts
200
μA
0.4
Volts
Volts
+/-0
μA
all Transmitter outputs loaded
with 3k ohms to GND
Vcc = 0V, Vout = +/-2V
Infinite Duration
CL = 2500pF, RL = 3kΩ
+/-5.0
300
+/-6
Volts
Ohms
+/-8
20
240
mA
kbps
-5
Vcc = 5V,
T
a
=25°C
Vcc = 5V,
T
a
=25°C
Vcc = 5V,
T
a
=25°C
0.2
3
0.8
.2
.7
0.5
5
+5
Volts
Volts
2.8
.0
7
Volts
Volts
kΩ
T
a
=
25°C
,
-15V ≤ V
in
≤ +15V
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)668-7000 • www.exar.com SP202E,232E,233E, 30E, 32E_00_0608
2
DETAiLED DESCRiPTion
The SP202E, SP232E, SP233E, SP30E and
SP32A devices are a family of line driver and
receiver pairs that meet the EIA/TIA-232 and
V.28 serial communication protocols. The ESD
tolerance has been improved on these devices
to over +/-5kV for Human Body Model. These
devices are pin-to-pin compatible with Exar's
232A, 233A, 30A and 32A as well as popular
industry standards. This family of parts offer a
20kbps data rate, 0V/
μ
s slew rate and an on-
board charge pump that operates from a single
5V supply using 0.
μ
F ceramic capacitors.
The SP202E, 232E, 233E, 30E and 32E de-
vices have internal charge pump voltage con-
verters which allow them to operate from a sin-
gle +5V supply. The charge pumps will operate
with polarized or non-polarized capacitors rang-
ing from 0. to 0µF and will generate the +/-6V
needed to generate the RS-232 output levels.
The SP233E design offers internal charge pump
capacitors. The SP30E provides an ON/OFF
input that simultaneously disables the internal
charge pump circuit and puts all transmitter and
receiver outputs into a high impedance state.
The SP32E is identical to the SP30E but with
seperate tri-state and shutdown inputs
Theory of operation
The SP202E, SP232E, SP233E, SP30E and
SP32E devices are made up of three basic
circuit blocks: 1. Drivers, 2. Receivers, and 3.
charge pump. Each block is described below.
Drivers
The drivers are inverting level transmitters that
convert TTL or CMOS logic levels to EIA/TIA-
232 levels with an inverted sense relative to
the input logic levels. The typical driver output
voltage swing is +/-6V. Even under worst case
loading conditions of 3k ohms and 2500pF, the
driver output is guaranteed to be +/-5.0V mini-
mum, thus satisfying the RS-232 specification.
The driver outputs are protected against infinite
short-circuits to ground without degradation in
reliability.
The slew rate of the driver output is internally
limited to 30V/
μ
s in order to meet the EIA stan-
dards (EIA-232F). Additionally, the driver out-
puts LOW to HIGH transition meets the mon-
tonic output requirements of the standard.
Receivers
The receivers convert EIA/TIA-232 signal lev-
els to inverted TTL or CMOS logic output lev-
els. Since the input is usually from a transmis-
sion 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 receiver is virtually immune to
noisy transmission lines. The input thresholds
are 0.8V minimum and 2.8V maximum, again
well within the +/-3V RS-232 requirements.
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.
DESCRiPTion
In actual system applications, it is quite pos-
sible for signals to be applied to receiver inputs
before power is applied to the receiver circuitry.
This occurs, for example, when a PC user at-
tempts to print, only to realize that the printer
wasn't turned on. In this case an RS-232 signal
from the PC will appear on the receiver input
at the printer. When the printer power is turned
on, the receiver will operate normally. All of
these devices are fully protected.
Charge pump
The charge pump is an Exar patented design
and uses a unique approach compared to
older less efficiant designs. The charge pump
requires 4 external capacitors and uses a four
phase voltage shifting technique. The internal
power supply consists of a dual charge pump
that provides a driver output voltage swing of
+/-6V. The internal oscillator controls the four
phases of the voltage shifting. A description of
each phase follows:
Phase 1
Vss charge store and double: The positive ter-
minals of capacitors C and C2 are charged
from Vcc with their negative terminals initially
connected to ground. C+ is then connected
to ground and the stored charge from C- is
superimposed onto C2-. Since C2+ is still con-
nected to Vcc the voltage potential across C2
is now 2 x Vcc.
Phase 2
Vss transfer and invert: Phase two connects
the negative terminal of C2 to the Vss storage
capacitor and the positive terminal of C2 to
ground. This transfers the doubled and invert-
ed (V-) voltage onto C4. Meanwhile, capacitor
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)668-7000 • www.exar.com SP202E,232E,233E, 30E, 32E_00_0608
5
51mcu
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