SP3220EA-L/TR [SIPEX]
Line Transceiver, 1 Func, 1 Driver, 1 Rcvr, PDSO16, LEAD FREE, PLASTIC, SSOP-16;
| 型号： | SP3220EA-L/TR |
| 厂家： | 
SIPEX CORPORATION |
| 描述： | Line Transceiver, 1 Func, 1 Driver, 1 Rcvr, PDSO16, LEAD FREE, PLASTIC, SSOP-16 |
| 文件： | 总19页 (文件大小：241K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
®
SP3238
Intelligent +3.0V to +5.5V RS-232 Transceiver
FEATURES
1
2
3
4
5
6
7
28
27
26
25
24
23
C2+
GND
C2-
V-
C1+
V+
■ Meets true EIA/TIA-232-F Standards
from a +3.0V to +5.5V power supply
■ Interoperable with EIA/TIA-232 and
adheres to EIA/TIA-562 down to a +2.7V
power source
V
CC
C1-
IN
T
T
T
OUT
1
1
SP3238
T
IN
OUT
OUT
2
3
2
22
T
T
IN
®
3
■ AUTO ON-LINE circuitry automatically
R
IN
IN
8
9
21
20
19
18
17
16
R
R
OUT
1
1
wakes up from a 1µA shutdown
■ Minimum 250Kbps data rate under load
■ Regulated Charge Pump Yields Stable
RS-232 Outputs Regardless of VCC
Variations
R
OUT
2
2
10
T
T
OUT
T
IN
4
4
R3IN 11
OUT
R
T
OUT
3
IN
12
5
5
ONLINE 13
R
OUT
1
SHUTDOWN 14
15
STATUS
■ ESD Specifications:
+2kV Human Body Model
Now Available in Lead Free Packaging
DESCRIPTION
The SP3238 device is an RS-232 transceiver solution intended for portable or hand-held
applications such as notebook and palmtop computers. The SP3238 uses an internal
high-efficiency, charge-pump power supply that requires only 0.1µF capacitors in 3.3V
operation. This charge pump and Sipex's driver architecture allow the SP3238 device to
deliver compliant RS-232 performance from a single power supply ranging from +3.0V to
+5.0V. The SP3238 is a 5-driver/3-receiver device, ideal for laptop/notebook computer and
PDA applications. The SP3238 includes one complementary receiver that remains alert to
monitor an external device's Ring Indicate signal while the device is shutdown.
®
TheAUTOON-LINE featureallowsthedevicetoautomatically"wake-up"duringashutdown
statewhenanRS-232cableisconnectedandaconnectedperipheralisturnedon. Otherwise,
the device automatically shuts itself down drawing less than 1µA.
SELECTION TABLE
AUTO ON-LINE®
Device
Power Supplies RS-232
RS-232
External
TTL 3-State
No. of
Pins
Drivers Receivers Components
Circuitry
SP3220
SP3223
SP3243
SP3238
+3.0V to +5.5V
+3.0V to +5.5V
+3.0V to +5.5V
+3.0V to +5.5V
1
2
3
5
1
2
5
3
4 capacitors
4 capacitors
4 capacitors
4 capacitors
NO
YES
YES
YES
YES
YES
YES
YES
16
20
28
28
Applicable U.S. Patents - 5,306,954; and other patents pending.
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation
of the device at these ratings 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 and cause permanent damage to the
device.
Power Dissipation per package
28-pin SSOP
(derate 11.2mW/oC above +70oC).................900mW
28-pin TSSOP
(derate 13.2mW/oC above +70oC)...............1100mW
V
CC.......................................................-0.3V to +6.0V
V+ (NOTE 1).......................................-0.3V to +7.0V
V- (NOTE 1)........................................+0.3V to -7.0V
V+ + |V-| (NOTE 1)...........................................+13V
I
CC (DC V or GND current).........................+100mA
InputVoltCaCges
TxIN, ONLINE,
SHUTDOWN, .....................................-0.3V to +6.0V
RxIN...................................................................+25V
OutputVoltages
TxOUT.............................................................+13.2V
RxOUT, STATUS.......................-0.3V to (VCC + 0.3V)
Short-CircuitDuration
TxOUT.....................................................Continuous
Storage Temperature......................-65°C to +150°C
Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
ELECTRICAL CHARACTERISTICS
= +3.0 to +5.5, C1 -C4 = 0.1µF (tested at 3.3V + 5%), C1-C4 = 0.22µF (tested at 3.3V + 10%), C1 = 0.047µF, and C2-C4 = 0.33µF (tested at 5.0V
V
+C1C0%), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
MIN.
TYP.
MAX. UNITS CONDITIONS
DC CHARACTERISTICS
Supply Current, AUTO ON-LINE®
µA
1.0
10
All RxIN open, ONLINE = GND,
SHUTDOWN = VCC, all TxIN=GND
or VCC
µA
Supply Current, Shutdown
1.0
0.3
10
SHUTDOWN=GND, all TxIN=GND
or VCC
Supply Current, AUTO ON-LINE®
Disabled
1.0
ONLINE = SHUTDOWN = VCC
,
mA
no load, all TxIN=GND or VCC
LOGIC INPUTS AND RECEIVER OUTPUTS
Input Logic Threshold
LOW
V
= +3.3V or +5.0V, TxIN
0.8
V
OCNCLINE, SHUTDOWN
HIGH
2.4
µA
Input Leakage Current
+0.01
+0.05
+1.0
TxIN, ONLINE, SHUTDOWN
TA = 25° C
µA
V
Output Leakage Current
Output Voltage LOW
Output Voltage HIGH
+10
0.4
Receivers Disabled
IOUT = 1.6mA
VCC - 0.6 VCC - 0.1
V
IOUT = -1.0mA
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
2
ELECTRICAL CHARACTERISTICS
V
= +3.0 to +5.5, C1 -C4 = 0.1µF (tested at 3.3V + 5%), C1-C4 = 0.22µF (tested at 3.3V + 10%), C1 = 0.047µF, and C2-C4 = 0.33µF (tested at 5.0V
+C1C0%), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
MIN.
TYP.
MAX. UNITS CONDITIONS
DRIVER OUTPUTS
Output Voltage Swing
±5.0
300
±5.4
V
All driver outputs loaded with 3KΩ
to GND
Ω
Output Resistance
VCC = V+ = V- = 0V, VOUT = ±2V
Output Short-Circuit Current
±35
±60
25
mA
V
OUT = GND
RECEIVER INPUTS
Input Voltage Range
Input Threshold LOW
Input Threshold LOW
Input Threshold HIGH
Input Threshold HIGH
Input Hysteresis
-25
0.6
0.8
V
V
1.2
1.5
1.5
1.8
0.5
5
V
V
V
V
CC = 3.3V
CC = 5.0V
CC = 3.3V
CC = 5.0V
V
2.4
2.4
V
V
V
Input Resistance
3
7
kΩ
AUTO ON-LINE® CIRCUITRY CHARACTERISTICS (ONLINE = GND, SHUTDOWN = VCC
)
STATUS Output Voltage LOW
STATUS Output Voltage HIGH
Receiver Threshold to Drivers
0.4
V
V
IOUT = 1.6mA
IOUT = -1.0mA
Figure 10
V
CC - 0.6
µS
200
0.5
Enabled (tONLINE
)
µS
µS
Receiver Positive or Negative
Threshold to STATUS HIGH
Figure 10
Figure 10
(tSTSH
)
Receiver Positive or Negative
Threshold to STATUS LOW
20
(tSTSL
)
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
3
ELECTRICAL CHARACTERISTICS
V
= +3.0 to +5.5, C1 -C4 = 0.1µF (tested at 3.3V + 5%), C1-C4 = 0.22µF (tested at 3.3V + 10%), C1 = 0.047µF, and C2-C4 = 0.33µF (tested at 5.0V
+C1C0%), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
MIN.
TYP.
MAX. UNITS CONDITIONS
TIMING CHARACTERISTICS
Maximum Data Rate
250
kbps
RL = 3kΩ, CL = 1000pF, one driver
switching
Receiver Propagation Delay
t
0.15
0.15
Receiver input to receiver output,
CL = 150pF
PHL
µS
t
PLH
Receiver Output Enable Time
Receiver Output Disable Time
Driver Skew
200
200
100
50
ns
ns
Normal operation
Normal operation
I tPLH - tPHL I,TA = 25OC
ns
Receiver Skew
ns
I tPLH - tPHL I
Transition-Region Slew Rate
30
V/µs
V
= 3.3V, R = 3kΩ, TAMB = 25OC,
mCeCasurementLs taken from -3.0V to
+3.0V or +3.0V to -3.0V
TYPICAL PERFOMANCE CHARACTERISTICS
Unless otherwise noted, the following perfomance characteristics apply for VCC = +3.3V, 250kbps data rate, all drivers loaded with 3kΩ, 0.1µF charge
pump capacitors, and TAMB = +25°C.
SLEW RATE vs. LOAD CAPACITANCE
TRANSMITTER OUTPUT vs. LOAD CAPACITANCE
25
20
15
10
5
6
4
2
POS. SR
NEG SR
VOH
VOL
0
0
1000
2000
3000
4000
5000
-2
-4
-6
0
0
1000
2000
3000
4000
5000
pF
pF
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
4
PIN DESCRIPTION
PIN
NO.
NAME
FUNCTION
C2+
GND
C2-
Positive terminal of the symmetrical charge-pump capacitor C2.
Ground.
1
2
Negative terminal of the symmetrical charge-pump capacitor C2.
Regulated -5.5V output generated by the charge pump.
RS-232 driver output.
3
V-
4
T1OUT
T2OUT
T3OUT
R1IN
5
RS-232 driver output.
6
RS-232 driver output.
7
RS-232 receiver input.
8
R2IN
RS-232 receiver input.
9
T4OUT
R3IN
RS-232 driver output.
10
11
12
RS-232 receiver input.
T5OUT
RS-232 driver output.
Apply logic HIGH to override AUTO ON-LINE® circuitry keeping drivers active
ONLINE
13
14
(SHUTDOWN must also be logic HIGH, refer to Table 2).
Apply logic LOW to shut down drivers and charge pump. This overrides all AUTO
ON-LINE® circuitry and ONLINE (refer to Table 2).
SHUTDOWN
STATUS
R1OUT
T5IN
TTL/CMOS Output indicating if a RS-232 signal is present on any receiver input.
Non-inverting receiver-1 output, active in shutdown.
TTL/CMOS driver input.
15
16
17
18
19
20
21
22
23
24
25
26
27
28
R3OUT
T4IN
TTL/CMOS receiver output.
TTL/CMOS driver input.
R2OUT
R1OUT
T3IN
TTL/CMOS receiver output.
TTL/CMOS receiver output.
TTL/CMOS driver input.
T2IN
TTL/CMOS driver input.
T1IN
TTL/CMOS driver input.
C1-
Negative terminal of the symmetrical charge-pump capacitor C1.
+3.0V to +5.5V supply voltage.
VCC
V+
Regulated +5.5V output generated by the charge pump.
Positive terminal of the symmetrical charge-pump capacitor C1
C1+
Table 1. Device Pin Description
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
5
TYPICAL PERFORMANCE CHARACTERISTICS
Unless otherwise noted, the following performance characteristics apply for VCC = +3.3V, 250kbps data rate, all drivers
loaded with 3kΩ, 0.1µF charge pump capacitors, and TAMB = +25°C.
SUPPLY CURRENT vs LOAD CAPACITANCE
60
50
40
250Kbps
30
20
10
0
120Kbps
20Kbps
0
1000
2000
3000
4000
5000
pF
Figure 3. Supply Current VS. Load Capacitance when
Transmitting Data
1
2
3
4
5
6
7
28
27
26
25
24
C2+
GND
C2-
V-
C1+
V+
VCC
C1-
T IN
1
T OUT
1
SP3238
23 T IN
2
T OUT
2
22
T OUT
3
T IN
3
R IN
1
8
9
21 R OUT
1
R IN
2
20
19
18
17
R OUT
2
10
T OUT
4
T IN
4
R3IN 11
T OUT
R OUT
3
T IN
5
12
5
ONLINE 13
16 R OUT
1
SHUTDOWN 14
15
STATUS
Figure 4. SP3238 Pinout Configuration
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
6
VCC
+
+
26
0.1µF
0.1µF
C5
C1
VCC
28
27
4
C1+
V+
V-
+
+
0.1µF
0.1µF
C3
C4
25
1
C1-
SP3238
C2+
+
C2
0.1µF
3
C2-
T1IN
T2IN
T3IN
T1OUT
T2OUT
T3OUT
T4OUT
T5OUT
5
24
23
6
22
19
17
7
RS-232
TTL/CMOS
INPUTS
OUTPUTS
T4IN
T5IN
10
12
R1OUT
R1OUT
16
21
R1IN
R2IN
R3IN
8
5kΩ
TTL/CMOS
OUTPUTS
R2OUT
R3OUT
9
20
18
RS-232
INPUTS
5kΩ
5kΩ
11
V
CC
14
13
SHUTDOWN
ONLINE
To µP Supervisor
15
STATUS
Circuit
GND
2
Figure 5. SP3238 Typical Operating Circuit
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
7
DESCRIPTION
The SP3238 device meets the EIA/TIA-232 and
ITU-T V.28/V.24 communication protocols and
can be implemented in battery-powered, por-
table, or hand-held applications such as
notebook or palmtop computers. The SP3238
device features Sipex's proprietary and patented
(U.S. #5,306,954) on-board charge pump
circuitry that generates ±5.5V RS-232 voltage
levels from a single +3.0V to +5.5V power
supply. The SP3238 device can guarantee a data
rate of 250kbps fully loaded.
The SP3238 device is an ideal choice for
power sensitive designs. The SP3238 device
features AUTO ON-LINE circuitry which re-
®
duces the power supply drain to a 1µA supply
current. In many portable or hand-held applica-
tions, an RS-232 cable can be disconnected or a
connected peripheral can be turned off. Under
these conditions, the internal charge pump and
the drivers will be shut down. Otherwise, the
system automatically comes online. This feature
allows design engineers to address power saving
concerns without major design changes.
The SP3238 is a 5-driver/3-receiver device,
ideal for portable or hand-held applications.
The SP3238 includes one complementary
always-active receiver that can monitor an
external device (such as a modem) in shutdown.
This aids in protecting the UART or serial
controller IC by preventing forward biasing
of the protection diodes where VCC may be
disconnected.
THEORY OF OPERATION
The SP3238 device is made up of four basic
circuit blocks: 1. Drivers, 2. Receivers,
3. the Sipex proprietary charge pump, and
®
4. AUTO ON-LINE circuitry.
Drivers
The drivers are inverting level transmitters that
convert TTL or CMOS logic levels to 5.0V EIA/
TIA-232 levels with an inverted sense relative to
the input logic levels. Typically, the RS-232
output voltage swing is +5.4V with no load and
+5V minimum fully loaded. The driver outputs
are protected against infinite short-circuits to
ground without degradation in reliability. These
drivers comply with the EIA-TIA-232F and all
previous RS-232 versions.
V
CC
+
+
26
CC
0.1µF
0.1µF
C5
C1
V
28
27
4
C1+
V+
V-
+
+
C3
C4
0.1µF
0.1µF
25
1
C1-
C2+
SP3238
+
C2
0.1µF
3
24
23
22
19
C2-
T1IN
T1OUT
T2OUT
5
RxD
CTS
DSR
DCD
RI
T2IN
6
T
3OUT
T
3IN
T4IN
5IN
7
RS-232
OUTPUTS
T4OUT
10
12
UART
or
The drivers can guarantee a data rate of 250kbps
fully loaded with 3kΩ in parallel with 1000pF,
ensuring compatibility with PC-to-PC commu-
nication software. All unused driver inputs must
be connected to VCC or GND.
T
5OUT
T
17
Serial µC
R1OUT
16
21
R1IN
R2IN
R3IN
R
1OUT
TxD
RTS
DTR
8
5kΩ
R2OUT
20
18
9
RS-232
INPUTS
5kΩ
5kΩ
R
3OUT
11
VCC
14
13
SHUTDOWN
ONLINE
15
STATUS
The slew rate of the driver output is internally
limited to a maximum of 30V/µs in order to
meet the EIA standards (EIA RS-232D 2.1.7,
Paragraph 5). The transition of the loaded
output from HIGH to LOW also meets the
monotonicity requirements of the standard.
GND
2
µP
Supervisor
IC
V
RESET
IN
Figure6.InterfaceCircuitryControlledby
Microprocessor Supervisory Circuit
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
8
Figure7showsaloopbacktestcircuitusedtotest
the RS-232 Drivers. Figure 8 shows the test
results of the loopback circuit with all five driv-
ers active at 120kbps with typical RS-232 loads
in parallel with 1000pF capacitors. Figure 6 shows
the test results where one driver was active at
250kbps and all five drivers loaded with an RS-
232 receiver in parallel with a 1000pF capacitor.
AsolidRS-232datatransmissionrateof120kbps
provides compatibility with many designs in
personal computer peripherals and LAN appli-
cations.
V
CC
+
+
0.1µF
0.1µF
C5
C1
V
CC
C1+
V+
V-
+
+
C3
C4
0.1µF
0.1µF
C1-
C2+
SP3238
+
C2
0.1µF
C2-
TxOUT
RxIN
TxIN
LOGIC
INPUTS
1000pF
RxOUT
LOGIC
OUTPUTS
5kΩ
VCC
ONLINE
Receivers
The receivers convert ±5.0V EIA/TIA-232
SHUTDOWN
GND
levels to TTL or CMOS logic output levels.
Receivers are not active when in shutdown. If
there is no activity present at the receivers for a
period longer than 100µs during AUTO ON-
LINE mode or when SHUTDOWN is enabled,
the device goes into a standby mode where the
circuit draws 1µA.
Figure 7. Loopback Test Circuit for RS-232 Driver Data
Transmission Rates
®
Indicator (RI) from a peripheral to be monitored
without forward biasing the TTL/CMOS inputs
of the other devices connected to the receiver
outputs.
The truth table logic of the driver and receiver
outputs can be found in Table 2.
Sincereceiverinputisusuallyfromatransmission
line where long cable lengths and system
interference can degrade the signal, the inputs
haveatypicalhysteresismarginof300mV. This
ensures that the receiver is virtually immune to
The SP3238 includes an additional non-
invertingreceiverwithanoutput R1OUT.R1OUT
is an extra output that remains active and monitors
activity while the other receiver outputs are
forced into high impedance. This allows Ring
Figure 8. Loopback Test Circuit Result at 120kbps
(All Drivers Fully Loaded)
Figure 9. Loopback Test Circuit result at 250kbps
(All Drivers Fully Loaded)
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
9
noisy transmission lines. Should an input be left
unconnected, an internal 5kΩ pulldown resistor
to ground will commit the output of the receiver
to a HIGH state.
Phase 3 (Figure 14)
— VDD charge storage — The third phase of the
clock is identical to the first phase — the charge
transferred in C1 produces –VCC in the negative
terminal of C1, which is applied to the negative
+
side of capacitor C2. Since C2 is at VCC, the
voltage potential across C2 is 2 times VCC
Charge Pump
.
The charge pump is a Sipex–patented design
(U.S. #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 attain symmetrical 5.5V
power supplies. The internal power supply
consists of a regulated dual charge pump that
provides output voltages 5.5V regardless of the
input voltage (VCC) over the +3.0V to +5.5V
range. This is important to maintain compliant
RS-232 levels regardless of power supply
fluctuations.
Phase 4 (Figure 15)
— VDD transfer — The fourth phase of the clock
connects the negative terminal of C2 to GND,
and transfers this positive generated voltage
across C2 to C4, the VDD storage capacitor. This
voltage is regulated to +5.5V. At this voltage,
the internal oscillator is disabled. Simultaneous
with the transfer of the voltage to C4, the
positive side of capacitor C1 is switched to VCC
and the negative side is connected to GND,
allowing the charge pump cycle to begin again.
The charge pump cycle will continue as long as
the operational conditions for the internal
oscillator are present.
The charge pump operates in a discontinuous
mode using an internal oscillator. If the output
voltages are less than a magnitude of 5.5V, the
charge pump is enabled. If the output voltages
exceed a magnitude of 5.5V, the charge pump is
disabled. Thisoscillatorcontrolsthefourphases
of the voltage shifting (Figure 13). A descrip-
tion of each phase follows.
+
–
Since both V and V are separately generated
+
–
from VCC, in a no–load condition V and V will
besymmetrical. Olderchargepumpapproaches
–
+
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.
The clock rate for the charge pump typically
operatesat500kHz. Theexternalcapacitorscan
be as low as 0.1µF with a 16V breakdown
voltage rating.
Phase 1 (Figure 11)
— VSS charge storage — During this phase of
the clock cycle, the positive side of capacitors
+
C1 and C2 are initially charged to VCC. Cl is
–
then switched to GND and the charge in C1 is
–
+
transferred to C2 . Since C2 is connected to
VCC, the voltage potential across capacitor C2 is
now 2 times VCC
.
Phase 2 (Figure 12)
— VSS transfer — Phase two of the clock
connects the negative terminal of C2 to the VSS
storage capacitor and the positive terminal of C2
to GND. This transfers a negative generated
voltage to C3. This generated voltage is
regulated to a minimum voltage of -5.5V.
Simultaneous with the transfer of the voltage to
C3, the positive side of capacitor C1 is switched
to VCC and the negative side is connected to
GND.
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
10
S
H
U
T
+2.7V
0V
RECEIVER
RS-232 INPUT
VOLTAGES
D
O
W
N
-2.7V
VCC
0V
STATUS
t
STSL
t
STSH
t
ONLINE
+5V
DRIVER
RS-232 OUTPUT
VOLTAGES
0V
-5V
Figure 10. AUTO ON-LINE® Timing Waveforms
V
= +5V
CC
C
+5V
4
+
–
+
V
V
Storage Capacitor
Storage Capacitor
DD
SS
+
–
+
–
C
C
2
1
–
C
–5V
–5V
3
Figure11. ChargePump—Phase1
V
= +5V
CC
C
4
+
–
+
V
Storage Capacitor
DD
+
–
+
C
C
2
1
–
–
V
Storage Capacitor
SS
C
–10V
3
Figure12. ChargePump—Phase2
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
11
[
T
]
+6V
a) C2+
T
T
0V
0V
1
2
2
b) C -
2
-6V
Ch1 2.00V Ch2 2.00V M 1.00µs Ch1 1.96V
Figure13.ChargePumpWaveforms
V
= +5V
CC
C
+
+5V
4
–
+
V
V
Storage Capacitor
Storage Capacitor
DD
+
–
+
–
C
C
2
1
–
SS
C
–5V
–5V
3
Figure14. ChargePump—Phase3
V
= +5V
CC
C
+
+10V
4
–
V
V
Storage Capacitor
Storage Capacitor
DD
+
+
–
C
C
2
1
–
+
–
SS
C
3
Figure15. ChargePump—Phase4
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
12
V
CC
+
26
0.1µF
0.1µF
C5
C1
28
C1+
+
27
4
25
1
C1-
V+
V-
+
+
C3
C4
0.1µF
0.1µF
SP3238
C2+
+
C2
0.1µF
3
16
21
C2-
R1OUT
R1IN
R2IN
R3IN
R1OUT
R2OUT
R3OUT
8
5kΩ
9
20
18
5kΩ
5kΩ
11
T1OUT
T2OUT
T3OUT
T4OUT
T5OUT
T1IN
T2IN
T3IN
T4IN
T5IN
5
24
23
22
19
17
6
7
10
12
DB-9
Connector
V
CC
14
13
SHUTDOWN
ONLINE
1
2
3
4
5
6
To µP Supervisor
Circuit
15
STATUS
7
8
9
2
DB-9 Connector Pins:
1. Received Line Signal Detector 6. DCE Ready
2. Received Data
7. Request to Send
8. Clear to Send
9. Ring Indicator
3. Transmitted Data
4. Data Terminal Ready
5. Signal Ground (Common)
Figure 16. Circuit for the connectivity of the SP3238 with a DB-9 connector
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
13
SHUTDOWN ONLINE
RS-232 SIGNAL AT
RECEIVER INPUT
STATUS
OUTPUT
TRANSCEIVER
STATUS
TXOUT RXOUT R1OUT
INPUT
INPUT
HIGH
-
YES
NO
HIGH
LOW
LOW
Active
Active
Active
Active
Active
Active
Active
Normal Operation
Normal Operation
HIGH
HIGH
HIGH
LOW
Shutdown
NO (>100µs)
High-Z Active
(AUTO ON-LINE®
)
LOW
LOW
-
-
YES
NO
HIGH
LOW
High-Z High-Z
High-Z High-Z
Active
Active
Shutdown
Shutdown
Table 2. AUTO ON-LINE® Logic
R INACT
X
Inactive Detection Block
RS-232
Receiver Block
R OUT
X
R IN
X
Figure 17. Stage I of AUTO ON-LINE® Circuitry
Delay
Stage
Delay
Stage
Delay
Stage
STATUS
R2INACT
R3INACT
R1INACT
Figure 18. Stage II of AUTO ON-LINE® Circuitry
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
14
®
AUTO ON-LINE Circuitry
When the drivers or internal charge pump are
disabled, the supply current is reduced to 1µA.
This can commonly occur in hand-held or
portable applications where the RS-232 cable is
disconnected or the RS-232 drivers of the
connected peripheral are turned off.
The SP3238 device has a patent pending
AUTOON-LINE® circuitryonboardthatsaves
power in applications such as laptop computers,
palmtop (PDA) computers, and other portable
systems.
The SP3238 device incorporates an
AUTO ON-LINE® circuit that automatically
enables itself when the external transmitters are
enabledandthecableisconnected. Conversely,
the AUTO ON-LINE® circuit also disables
most of the internal circuitry when the device is
not being used and goes into a standby mode
where the device typically draws 1µA. This
functionisexternallycontrolledbytheONLINE
pin. When this pin is tied to a logic LOW, the
AUTO ON-LINE® function is active. Once
active, the device is enabled until there is no
activity on the receiver inputs. The receiver
input typically sees at least +3V, which are
generated from the transmitters at the other end
of the cable with a +5V minimum. When the
external transmitters are disabled or the cable is
disconnected, the receiver inputs will be pulled
down by their internal 5kΩ resistors to ground.
When this occurs over a period of time, the
internal transmitters will be disabled and the
device goes into a shutdown or standby mode.
When ONLINE is HIGH, the AUTO ON-
LINE® mode is disabled.
The AUTO ON-LINE® mode can be disabled
by the SHUTDOWN pin. If this pin is a logic
LOW, the AUTO ON-LINE® function will not
operate regardless of the logic state of the
ONLINE pin. Table 2 summarizes the logic of
the AUTO ON-LINE® operating modes and
the truth table logic of the driver and receiver
outputs.
The STATUS pin outputs a logic LOW signal
when there is no valid RS-232 signal present on
any receiver input. This pin goes to a
logic HIGH when the external transmitters are
enabled and the cable is connected.
When the SP3238 device is shut down, the
charge pump is turned off. V+ charge pump
output decays to VCC, the V- output decays to
GND. The decay time will depend on the size of
capacitors used for the charge pump. Once in
shutdown, the time required to exit the shut
down state and have valid V+ and V- levels is
typically 200ms.
The AUTO ON-LINE® circuit has two stages:
1) Inactive Detection
For easy programming, the STATUS pin can be
used to indicate DTR or a Ring Indicator signal.
Tying ONLINE and SHUTDOWN together
will bypass the AUTO ON-LINE® circuitry so
this connection acts like a shutdown input pin.
2) Accumulated Delay
The first stage, shown in Figure 17, detects an
inactive input. A logic HIGH is asserted on
RXINACT if the cable is disconnected or the
external transmitters are disabled. Otherwise,
RXINACT will be at a logic LOW. This circuit
is duplicated for each of the other receivers.
The second stage of the AUTO ON-LINE®
circuitry, shown in Figure 18, processes all the
receiver's RXINACT signals with an accumu-
lated delay that disables the device to a 1µA
supply current.
The STATUS pin goes to a logic LOW when the
cableisdisconnectedorwhentheexternaltrans-
mitters are disabled.
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
15
ESD TOLERANCE
The SP3238 device incorporates ruggedized
ESD cells on all driver output and receiver input
pins. The ESD structure is improved over our
previous family for more rugged applications
and environments sensitive to electro-static
discharges and associated transients.
The Human Body Model has been the generally
acceptedESDtestingmethodforsemiconductors.
This method is also specified in MIL-STD-883,
Method 3015.7 for ESD testing. The premise of
this ESD test is to simulate the human body’s
potential to store electro-static energy and
discharge it to an integrated circuit. The
simulation is performed by using a test model as
shown in Figure 19. This method will test the
IC’s capability to withstand an ESD transient
duringnormalhandlingsuchasinmanufacturing
areaswheretheICstendtobehandledfrequently.
FortheHumanBodyModel, thecurrentlimiting
resistor (RS) and the source capacitor (CS) are
1.5kΩ and 100pF, respectively.
R
R
S
S
R
R
C
C
SW2
SW2
SW1
SW1
Device
Under
Test
DC Power
Source
C
C
S
S
Figure 19. ESD Test Circuit for Human Body Model
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
16
PACKAGE: PLASTIC SHRINK
SMALL OUTLINE
(SSOP)
E
H
D
A
Ø
A1
L
e
B
DIMENSIONS (Inches)
Minimum/Maximum
(mm)
28–PIN
A
A1
B
D
E
0.068/0.078
(1.73/1.99)
0.002/0.008
(0.05/0.21)
0.010/0.015
(0.25/0.38)
0.397/0.407
(10.07/10.33)
0.205/0.212
(5.20/5.38)
e
0.0256 BSC
(0.65 BSC)
H
L
0.301/0.311
(7.65/7.90)
0.022/0.037
(0.55/0.95)
Ø
0°/8°
(0°/8°)
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
17
PACKAGE: 20 PIN TSSOP
D
e
Ø
E
E1
Seaing Plane
Ø
L
Ø
L1
DETAIL A
1
2
INDEX AREA
D
2
E1
x
2
SEE DETAIL “A”
A2
A
Seating Plane
A1
b
B
B
20 Pin TSSOP JEDEC MO-153 (AC)
Variation
MIN
-
0.05
0.8
0.19
0.09
6.4
NOM
MAX
1.2
0.15
1.05
0.3
SYMBOL
A
A1
A2
b
c
D
-
-
1
-
-
6.5
b
0.2
6.6
E
E1
e
Ø1
ø2
ø3
L
6.40 BSC
4.4
0.65 BSC
-
12º REF
12º REF
0.6
C
4.3
0º
4.5
8º
Section B-B
0.45
0.75
L1
1.00 REF
Note: Dimensions in (mm)
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
18
ORDERING INFORMATION
Model
Temperature Range
0°C to +70°C
Package Types
28-pin SSOP
28-pin SSOP
28-pin TSSOP
28-pin TSSOP
SP3238CA
SP3238CA/TR
SP3238CY
SP3238CY/TR
0°C to +70°C
0°C to +70°C
0°C to +70°C
SP3238EA
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
28-pin SSOP
28-pin SSOP
28-pin TSSOP
28-pin TSSOP
SP3238EA/TR
SP3238EY
SP3238EY/TR
Available in lead free packaging. To order add “-L” suffix to part number.
Example: SP3238EA/TR = standard; SP3238EA-L/TR = lead free
/TR = Tape and Reel
Pack quantity is 1,500 for SSOP and TSSOP.
CLICK HERE TO ORDER SAMPLES
Corporation
ANALOGEXCELLENCE
Sipex Corporation
Headquarters and
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 herein; neither does it convey any license under its patent rights nor the rights of others.
Rev. 6/30/03
SP3238 Intelligent +3.0V to +5.5V RS-232 Transceiver
© Copyright 2003 Sipex Corporation
19
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