SP206/207/208/211
+5V RS-232 Serial Transceivers
FEATURES
• 0.μF External Charge Pump Capacitors
• 20kbps Data Rate
• Standard SOIC and SSOP Packaging
• Multiple Drivers and Receivers
• Single 5V Supply Operation
• .0μA Shutdown Mode
• Tri-State Receiver Outputs
• Meets all RS-232F and V.28 Specifications
• Improved Driver Output Capacity for Mouse
Applications
• +/-0kV ESD Protection*
T
3
OUT
T
1
OUT
T
2
OUT
R
1
IN
R
1
OUT
T
2
IN
T
1
IN
GND
V
CC
C
1
+
V+
C
1
–
1
2
3
4
5
24
23
22
21
20
T
4
OUT
R
2
IN
R
2
OUT
SD
EN
T
4
IN
T
3
IN
R
3
OUT
R
3
IN
V–
C
2
–
C
2
+
SP206
6
7
8
9
10
11
12
19
18
17
16
15
14
13
Now Available in Lead Free Packaging
Note: See page 4 for other pinouts
The SP206, SP207, SP208 and SP2 are multi-channel RS-232 line transceivers in a variety of
configurations to fit most communication needs. All models in this series feature low-power CMOS
construction and Exar Patented (5,306,954) on-board charge pump circuitry to generate the +/-0V
RS-232 voltage levels, using 0.µF charge pump capacitors to save board space and reduce circuit
cost. The SP206 and SP2 models feature a low-power shutdown mode which reduces power sup-
ply drain to µA.
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
DESCRIPTION
SP206
SP207
SP208
SP2
4
5
4
4
3
3
4
5
0
0
0
0
4
4
4
4
Yes
No
No
Yes
No
No
No
No
Yes
No
No
Yes
Table . Mode Selection Table
* All Driver Outputs and Receiver Inputs characterized per MIL-STD-883C Method 305.7
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)668-7000 • Fax (50)668-707 • www.exar.com SP206, 207, 208, 2_0_060
These are stress ratings only and functional opera-
tion of the device at these ratings or any other above
those indicated in the operation sections of the speci-
fications below are not implied. Exposure to absolute
Package Power Dissipation:
maximum ratings conditions for extended periods of
24-pin SSOP
(derate .2mW/°C above +70°C..............900mW
time may affect reliability.
Supply Voltage (V
CC
)....................................................+ 6V
V+........................................................................... (Vcc-0.3V) to +3.2V
V- .............................................................................-3.2V
Input Voltages
Tin.....................................................-0.3V to (Vcc + 0.3V)
Rin............................................................................+/-20V
Output Voltages
Tout...............................................(V+, +0.3V) to (V-, -0.3V
Rout...................................................-0.3V to (Vcc + 0.3V)
Short Circuit duration on Tout...........................Continuous
AbSOlUTE MAxIMUM RATINgS
24-pin WSOIC
(derate 2.5mW/°C above +70°C............000mW
28-pin SSOP
(derate .2mW/°C above +70°C..............900mW
28-pin WSOIC
(derate 2.7mW/°C above +70°C............000mW
Storage Temperature..................-65°C to +50°C
Lead Temperature (soldering, 0s).......... +300°C
Vcc = 5V, C to C4 = 0.
μ
F, T
min
to T
max
, unless otherwise noted.
PARAMETER
TTl INPUT
Logic Threshold LOW, V
iL
Logic Threshold HIGH, V
iH
Logic Pull-Up Current
Maximum Data Rate
TTl OUTPUT
Output Voltage LOW, V
OL
Output Voltage HIGH, V
OH
Leakage Current
RS-232 OUTPUT
output Voltage Swing
Output Resistance
Output Short Circuit Current
RS-232 INPUT
Voltage Range
Voltage Threshold LOW
Voltage Threshold HIGH
Hysteresis
Resistance
Vcc = 5V, T
a
=25°C
Vcc = 5V, T
a
=25°C
Vcc = 5V
i
ouT
= 3.2ma: V
CC
= +5V
i
ouT
= -1.0ma
Tin, En, SD
Tin, En, SD
Tin = 0V
C
L
= 2500pF, R
L
= 3kΩ
TEST CONDITIONS
ElECTRICAl CHARACTERISTICS
MIN
TYP
MAx
UNIT
0.8
2.0
5
20
200
Volts
Volts
μA
kbps
0.4
3.5
0.05
+/-0
Volts
Volts
μA
En = V
CC
,
0V ≤ V
ouT
≤ Vcc
T
a
=25°C
all Transmitter outputs loaded
with 3k ohms to GND
Vcc = 0V, Vout = +/-2V
Infinite Duration
+/-5.0
300
+/-7
Volts
Ohms
+/-25
mA
-5
0.8
.2
.7
0.2
3
0.5
5
+5
Volts
Volts
2.4
.0
7
Volts
Volts
kΩ
T
a
=25°C
,
-15V ≤ V
in
≤ +15V
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)668-7000 • Fax (50)668-707 • www.exar.com SP206, 207, 208, 2_0_060
2
Vcc = 5.0V, C to C4 = 0.
μ
F, T
min
to T
max
, unless otherwise noted.
Parameter
DYNAMIC CHARACTERISTICS
Receiver Propagation Delay
Instantaneous Slew Rate
Transition Region Slew Rate
Output Enable Time
Output Disable Time
POWER REQUIREMENTS
Vcc (SP207)
Vcc (SP206, SP208 and SP2)
Vcc Power Supply Current
Vcc Power Supply Current, Loaded
Shutdown Supply Current
ENVIRONMENTAl AND MECHANICAl
Operating Temperature, Commercial, _C
Operating Temperature, Extended, _E
Storage Temperature
Package _A
Package _T
RS-232 to TTL,
TEST CONDITIONS
ElECTRICAl CHARACTERISTICS
MIN
TYP
MAX
Unit
.5
30
5
400
250
μs
V/ μs
V/ μs
ns
ns
C
L
= 50pF, R
L
= 3-7kΩ,
T
a
=25°C
C
L
= 2500pF, R
L
= 3kΩ;
Measured from +3V to -3V or
-3V to +3V
4.75
4.50
No Load, Vcc = +/-0%,T
a
=25°C
All Transmitters RL = 3kΩ,
T
a
=25°C
T
a
=25°C
5.00
5.00
4
20
5.25
5.5
0
Volts
Volts
mA
mA
0
μA
0
-40
-65
Shrink (SSOP) small outline
Wide (SOIC) small outline
+70
+85
+50
°C
°C
°C
Transmitter Output
R
L
= 3kΩ, C
L
= 5,000pF
Transmitter Output
R
L
= 3kΩ, C
L
= 2,500pF
Receiver Output
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)668-7000 • Fax (50)668-707 • www.exar.com SP206, 207, 208, 2_0_060
3
FEATURES
The SP206/207/208/2 multi-channel RS-232
line transceivers provide a variety of configu-
rations to fit most communication needs, es-
pecially those applications where +/-2V is not
available. All models in this series feature low-
power CMOS construction and Exar's proprie-
tary on-board charge pump circuitry to generate
the +/-0V RS-232 voltage levels. The ability to
use 0.µF charge pump capacitors saves board
space and reduces circuit cost. Different mod-
els within the series provide different driver/re-
ceiver combinations to match any application
requirement.
The SP206 and SP2 models feature a low-
power shutdown mode that reduces power sup-
ply drain to µA.
The models in this series are available in 24-pin
and 28-pin SO (wide) and SSOP (shrink) small
outline packages. Devices can be specified for
commercial (0ºC to +70ºC) or industrial/extend-
ed (-40ºC to +85ºC) operating temperatures.
THEORY OF OPERATION
CHARgE PUMP
The charge pump is an Exar patented design
and uses a unique approach compared to older
less-efficient designs. The charge pump still
requires four external capacitors, but uses a
four phase voltage shifting technique to attain
symmetrical +/-0V power supplies. Figure a
shows the waveform found on the positive side
of capacitor C2 and Figure 3b shows the nega-
tive side of capacitor C2. There is a free-run-
ning oscillator that controls the four phases of
the voltage shifting. A description of each phase
follows:
PHASE 1
Vss charge storage - During this phase of the
clock cycle, the positive side of capacitors C
and C2 are initially charged to +5V. C+ is then
switched to ground and the charge in C- is
transferred to C2-. Since C2+ is connected to
+5V, the voltage potential across capacitor C2
is now 0V.
PHASE 2
Vss transfer: Phase two of the clock connects
the negative terminal of C2 to the Vss stor-
age capacitor and the positive terminal of C2
to ground, and transfers the generated -0V to
C3. Simultaneously, the positive side of capaci-
tor C is switched to +5V and the negative side
is connected to ground.
PHASE 3
Vdd charge storage: The third phase of the
clock is identical to the first phase. The charge
transferred in C produces -5V in the negative
terminal of C, which is applied to the negative
side of C2. Since C2+ is at +5V, the voltage po-
tential across C2 is 0V.
PHASE 4
Vdd transfer: The fourth phase of the clock con-
nects the negative terminal of C2 to ground,
and transfers the generated 0V across C2 to
C4, the Vdd storage capacitor. Again, simulta-
neously with this, the positive side of capaci-
tor C is switched to +5V and the negative side
is connected to ground, and the cycle begins
again.
Since both V+ and V- are separately generated
from Vcc; in a no-load condition V+ and V- will
be symmetrical. Older charge pump approach-
es that generate V- from V+ will show a de-
crease in magnitude of V- compared to V+ due
to the inherent inefficiencies in the design.
The clock rate for the charge pump typically op-
erates at greater than 5kHz allowing the pump
to run efficiently with small 0.1uF capacitors
with a 6V breakdown voltage rating.
The SP206/207/208/2 devices are made up
of three basic circuit blocks - ) transmitter/
driver, 2) receiver and 3) charge pump. Each
model within the series incorporates variations
of these circuit to achieve the desired configu-
ration and performance.
DESCRIPTION
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)668-7000 • Fax (50)668-707 • www.exar.com SP206, 207, 208, 2_0_060
5
Embedded System
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