The SP207H and SP211H are multi–channel RS-232 line transceivers configured to fit most
communication needs. The "H" series is based on Sipex's SP200 Series transceivers and has
been enhanced for speed. The data rate is improved to over 460kbps which easily meets the
230.4kbps data rates for V.34. The SP207H and SP211H use the same on-board charge pump
to provide ±10V voltage levels, using 0.1µF charge pump capacitors to save board space and
reduce circuit cost. The SP207HB, SP211H and SP211HB feature a low–power shutdown
mode, which reduces power supply drain to 1µA. A WakeUp function keeps the receivers active
in the shutdown mode (SP207HB and SP211HB only).
+5V INPUT
10
0.1µF
+
0.1µF
6.3V
6.3V
12
13
+
0.1µF
16V
14
T1 IN
T2 IN
18
T3 IN
19
T4 IN
TTL/CMOS INPUTS
21
T5 IN
OUTR1 IN
R
1
22
R2 OUTR2 IN
17
R3 OUTR3 IN
TTL/CMOS OUTPUTS
0.1µF
9
6.3V
400KOHM
400KOHM
400KOHM
400KOHM
400KOHM
R
R
R
SP207
1
2
3
+
V
11
CC
V
+
0.1µF
16V
15
–
V
+
2
T
OUT
T
1
1
3
OUT
T
T
2
2
1
T
OUT
T
3
3
24
T
OUT
T
4
4
RS-232 OUTPUTS
20
T
OUT
T
5
5
4
5KOHM
23
5KOHM
16
5KOHM
8
GND
RS-232 INPUTS
+
C
1
–
C
1
C
+
2
–
C
2
7
6
5
+5V INPUT
0.1µF
+
0.1µF
6.3V
6.3V
+
0.1µF
16V
T1 IN
T2 IN
T3 IN
TTL/CMOS INPUTS
T4 IN
R
OUTR1 IN
1
R2 OUTR2 IN
R
OUTR3 IN
3
R4 OUTR4IN
TTL/CMOS OUTPUTS
R5 OUTR5 IN
EN
12
C
+
1
14
C
–
1
15
C
+
2
16
C
–
2
400KOHM
7
400KOHM
6
400KOHM
20
400KOHM
21
8
54
2627
2223
1918
24
6.3V
+
V
13
CC
+
V
0.1µF
16V
17
V
–
+
SP211
2
T
T
OUT
1
1
3
T
OUT
T
2
2
1
T
T
OUT
3
3
28
T
T
OUT
4
4
9
R
1
5KOHM
R
2
5KOHM
R
3
5KOHM
R
4
5KOHM
R
5
5KOHM
25
SD
10
GND
0.1µF
11
RS-232 OUTPUTS
RS-232 INPUTS
Number of RS-232No. of ReceiversNo. of External
Model Drivers Receivers Active in Shutdown 0.1µ F Capacitors Shutdown WakeUp TTL Tri–State
These are stress ratings only and functional operation of the device
at these or any other above those indicated in the operation
sections of the specifications below is not implied. Exposure to
absolute maximum rating conditions for extended periods of time
may affect reliability.
The SP207H and SP211H line transceivers
provide a variety of configurations to fit most
communication needs, especially those applications where ±12V is not available. Both prod-
THEORY OF OPERATION
The SP207H and SP211H are made up of three
basic circuit blocks — 1) transmitter/driver, 2)
receiver and 3) the Sipex–proprietary charge
pump.
ucts feature low–power CMOS construction
and Sipex–proprietary on-board charge pump
circuitry to generate the ±10V RS-232 voltage
levels. The ability to use 0.1µF charge pump
capacitors saves board space and reduces circuit
cost.
Charge–Pump
The charge pump is a Sipex–patented design
(5,306,954) 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
The SP207HB and SP211H models feature a
low–power shutdown mode, which reduces
power supply drain to 1µA. The SP207HB and
attain symmetrical 10V power supplies. Figure3a shows the waveform found on the positive
side of capcitor C2, and Figure 3b shows the
SP211HB are equipped with the WakeUp function. The WakeUp function keeps the receivers
active in the shutdown mode, unless disabled by
the EN pin.
negative side of capcitor C2. There is a free–
running 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
switched to ground and the charge in C
transferred to C
+5V, the voltage potential across capacitor C2 is
–
. Since C
2
+
is connected to
2
+
is then
l
–
is
1
now 10V.
Phase 2
— VSS transfer — Phase two of the clock connects the negative terminal of C2 to the V
storage capacitor and the positive terminal of C
to ground, and transfers the generated –l0V to
C3. Simultaneously, the positive side of capacitor C 1 is switched to +5V and the negative side
is connected to ground.
C
4
+
–
Storage Capacitor
V
DD
+
–
V
Storage Capacitor
SS
C
3
2
+5V
––
voltage potential across C2 is l0V.
Phase 4
— VDD transfer — The fourth phase of the clock
connects the negative terminal of C2 to ground,
and transfers the generated l0V across C2 to C4,
the VDD storage capacitor. Again, simultaneously
with this, the positive side of capacitor C1 is
1
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 approaches
that generate V– from V+ will show a decrease in
the magnitude of V– compared to V+ due to the
inherent inefficiencies in the design.
SS
2
The clock rate for the charge pump typically
operates at 15kHz. The external capacitors can
be as low as 0.1µF with a 16V breakdown
voltage rating.
Phase 3
— VDD charge storage — The third phase of the
clock is identical to the first phase — the charge
transferred in C1 produces –5V in the negative
terminal of C1, which is applied to the negative
side of capacitor C2. Since C
The drivers are inverting transmitters which have
been improved for speed over the SP200 Series.
The transmitters accept either TTL or CMOS
inputs and output the RS-232 signals at data rates
over 400kbps. Typically, the RS-232 output volt
C
4
+
–
Storage Capacitor
V
DD
+
–
V
Storage Capacitor
SS
C
3
5
Page 6
+10V
VCC = +5V
–5V
+5V
–5V
V
SS
Storage Capacitor
V
DD
Storage Capacitor
C
1
C
2
C
3
C
4
+
+
++
–
–
––
+
a) C
2
GND
GND
–
b) C
2
–10V
Figure 3. Charge Pump Waveforms
age 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 SP207HB,SP211H and SP211HB drivers can be tri–stated
by using the SHUTDOWN function.
In the “power off” state, the output impedance will
remain greater than 300 ohms, again satisfying the
RS-232 specifications. Should the input of the
driver be left open, an internal 400Kohm pullup
resistor to VCC forces the input high, thus committing the output to a low state.
Because of the increased speed, the slew rate is
typically 60V/µS which is above the RS-232
specifcation of 30V/µS. This is the only parameter that exceeds the RS-232 limits.
Receivers
The receivers convert RS-232 input signals to
inverted TTL 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 5Kohm pulldown
resistor to ground will commit the output of the
receiver to a high state.
The SP207HB, SP211H and SP211HB all fea-
ture a control input which will disable the device
and reduce the power supply current to less than
10µA, making the parts ideal for battery–powered systems. In the “shutdown” mode the receivers and transmitters will both be tri–stated.
The V+ output of the charge pump will discharge
to V
, and the V– output will discharge to
CC
ground.
For complete shutdown to occur and the 10µA
power drain to be realized, the following conditions must be met:
• +5V must be applied to the SD pin
• ENABLE must be either 0V, +5.0V or not
connected
• the transmitter inputs must be either +5.0V
or not connected
• VCC must be +5V
• Receiver inputs must be >0V and <+5V
ENABLE
The SP207HB, SP211H and SP211HB feature
an enable input pin, which allows the receiver
C
4
+
–
Storage Capacitor
V
DD
+
–
V
Storage Capacitor
SS
C
3
C
+10V
2
––
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 is active low; that is, 0V applied to the
ENABLE pin will enable the receiver outputs.
WAKEUP FUNCTION
The SP207HB and SP211HB have a wake–up
feature that keeps all the receivers in an enabled
state when the device is in the shutdown mode.
With only the receivers active during shutdown,
the devices draw 5–10µA of supply current. A
typical application of this function would be
where a modem is interfaced to a computer in a
power–down mode. The ring indicator signal
from the modem could be passed through an
active receiver that is in the shutdown mode.
The ring indicator signal would propagate
through the receiver to the power management
circuitry of the computer to power up the microprocessor and the SP207HB/SP211HB drivers.
After the supply voltage to the transceivers
reaches +5.0V, the SHUTDOWN pin can be
disabled. All receivers that are active during
shutdown maintain 500mV (typ.) of hysteresis.
SP207HET........ 5............................. 3 ............................ –40°C to +85°C............................... 24–pin SOIC
RS232 Transceivers with Low–Power Shutdown and Tri–state Enable:
Model .......... Drivers ............... Receivers..................... Temperature Range .................Package Type
SP211HCA ....... 4............................. 5 ................................0° C to +70°C.............................. 28–pin SSOP
SP211HCT ....... 4 ............................. 5 ................................0°C to +70°C............................... 28–pin SOIC
SP211HEA ....... 4............................. 5 ............................ –40°C to +85°C.............................. 28–pin SSOP
SP211HET........ 4............................. 5 ............................ –40°C to +85°C............................... 28–pin SOIC
RS232 Transceivers with Low–Power Shutdown, Tri–state Enable, and
Wake–Up Function:
Model .......... Drivers ............... Receivers..................... Temperature Range .................Package Type
SP207HBCA .... 5 ....... 3, with 3 active in Shutdown .......... 0°C to +70°C.............................. 28–pin SSOP
SP207HBCT..... 5 ....... 3, with 3 active in Shutdown .......... 0°C to +70°C............................... 28–pin SOIC
SP207HBEA..... 5....... 3, with 3 active in Shutdown ...... –40°C to +85°C.............................. 28–pin SSOP
SP207HBET ..... 5....... 3, with 3 active in Shutdown ...... –40°C to +85 °C ............................... 28–pin SOIC
SP211HBCA .... 4 ....... 5, with 5 active in Shutdown .......... 0°C to +70°C.............................. 28–pin SSOP
SP211HBCT..... 4 ....... 5, with 5 active in Shutdown .......... 0°C to +70°C............................... 28–pin SOIC
SP211HBEA..... 4....... 5, with 5 active in Shutdown ...... –40°C to +85°C.............................. 28–pin SSOP
SP211HBET ..... 4....... 5, with 5 active in Shutdown ...... –40°C to +85 °C ............................... 28–pin SOIC
Corporation
SIGNAL PROCESSING EXCELLENCE
Sipex Corporation
Headquarters and
Sales Office
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: sales@sipex.com
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others.