SIPEX SP3221EEY/TR

SP3221E
Intelligent +3.0V to +5.5V RS-232 Transceiver
■ Meets true EIA/TIA-232-F Standards
from a +3.0V to +5.5V power supply
■ Operates with EIA/TIA-232 and adheres
to EIA/TIA-562 down to a +2.7V power
source
■ Auto-Online™ circuitry allows 1µA
supply current when in shutdown
■ 240kbps data rate under load
■ 6V/µs minimum slew rate
■ The SP3221 is the industries smallest
single-supply RS-232 transceiver
package
■ Enhanced ESD Specifications:
+15KV Human Body Model
+15KV IEC1000-4-2 Air Discharge
+8KV IEC1000-4-2 Contact Discharge
EN
16 SHUTDOWN
1
C1+ 2
15 VCC
V+
3
C1-
4
13
T1OUT
C2+
5
12
ONLINE
C2-
6
11 T1IN
V-
7
10
STATUS
R1IN
8
9
R1OUT
14 GND
SP3221
Now Available in Lead Free Packaging
DESCRIPTION
The SP3221E is a RS-232 transceiver solution intended for portable or hand-held applications
such as notebook and palmtop computers. The SP3221E has a high-efficiency, charge-pump
power supply that requires only 0.1µF capacitors in 3.3V operation. This charge pump and low
dropout transmitters allow the SP3221E device to deliver true RS-232 performance from a
single power supply ranging from +3.3V to +5.0V. The Auto-Online feature allows the device
to automatically "wake-up" during a shutdown state when an RS-232 cable is connected .
Otherwise, the device automatically shuts itself down drawing less than 1µA.
SELECTION TABLE
Device
Power Supplies
RS-232
Drivers
RS-232
Receivers
External
Components
Auto-Online
Circuitry
TTL 3-State
No. of
Pins
SP3221E
+3.0V to +5.5V
1
1
4 (0.1µF)
capacitors
YES
YES
16
SP3220E
+3.0V to +5.5V
1
1
4 (0.1µF)
capacitors
NO
YES
16
Applicable U.S. Patents - 5,306,954; and other patents pending.
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
1
© Copyright 2004 Sipex Corporation
Power Dissipation per package
ABSOLUTE MAXIMUM RATINGS
16-pin PDIP (derate 14.3mW/oC above+70oC).....1150mW
16-pin SSOP (derate 9.69mW/oC above +70oC)....775mW
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.
VCC.......................................................-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
ICC (DC VCC or GND current)..........................+100mA
Input Voltages
TxIN, ONLINE,
SHUTDOWN, EN .................................-0.3V to +6.0V
RxIN....................................................................+15V
Output Voltages
TxOUT.................................................................+15V
RxOUT, STATUS..................-0.3V to (VCC + 0.3V)
Short-Circuit Duration
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.
SPECIFICATIONS
Unless otherwise noted, the following specifications apply for VCC = +3.0V to +5.5V with TAMB = TMIN to TMAX.
Typical values apply at VCC = +3.3V or +5.0V and TAMB = 25°C.
PARAMETER
MIN.
TYP.
MAX.
UNITS
CONDITIONS
Supply Current, Auto-Online
1.0
10
µA
All RxIN open, ONLINE = GND,
SHUTDOWN = VCC,
VCC = +3.3V, TAMB = +25° C
Supply Current, Shutdown
1.0
10
µA
SHUTDOWN = GND,
VCC = +3.3V, TAMB = +25° C
Supply Current, Auto-Online
Disabled
0.3
1.0
mA
ONLINE = SHUTDOWN = VCC,
no load, VCC = +3.3V, TAMB = +25° C
0.8
V
DC CHARACTERISTICS
LOGIC INPUTS AND RECEIVER OUTPUTS
Input Logic Threshold
LOW
HIGH
2.0
VCC = +3.3V or +5.0V, TxIN,
EN, ONLINE,
SHUTDOWN
Input Leakage Current
±0.01
±1.0
µA
TxIN, EN, ONLINE, SHUTDOWN,
TAMB = +25° C
Output Leakage Current
±0.05
±10
µA
Receivers disabled
0.4
V
IOUT = 1.6mA
V
IOUT = -1.0mA
Output Voltage LOW
Output Voltage HIGH
Date: 7/21/04
VCC - 0.6
VCC - 0.1
SP3221E +3.0V to +5.5V RS-232 Transceiver
2
© Copyright 2004 Sipex Corporation
SPECIFICATIONS (continued)
Unless otherwise noted, the following specifications apply for VCC = +3.0V to +5.5V with TAMB = TMIN to TMAX.
Typical values apply at VCC = +3.3V or +5.0V and TAMB = 25°C.
PARAMETER
MIN.
TYP.
Output Voltage Swing
± 5.0
± 5. 4
Output Resistance
30 0
MAX.
UNITS
CONDITIONS
DRIVER OUTPUTS
Output Short-Circuit Current
± 35
± 70
Output Leakage Current
V
All driver outputs loaded with 3KΩ
to GND, TAMB = +25° C
Ω
VCC = V+ = V- = 0V, VOUT = ± 2V
± 60
± 100
mA
± 25
µA
15
V
VOUT = 0V
VOUT = ± 15V
VCC = 0V or 3.0V to 5.5V,
VOUT = ± 12V, Drivers disabled
RECEIVER INPUTS
Input Voltage Range
-15
Input Threshold LOW
0.6
1.2
V
VCC = 3.3V
Input Threshold LOW
0. 8
1.5
V
VCC = 5.0V
Input Threshold HIGH
1. 5
2.4
V
VCC = 3.3V
Input Threshold HIGH
1. 8
2.4
V
VCC = 5.0V
Input Hysteresis
0. 3
Input Resistance
3
V
5
7
kΩ
Auto-Online CIRCUITRY CHARACTERISTICS (ONLINE = GND, SHUTDOWN = VCC)
STATUS Output Voltage LOW
STATUS Output Voltage HIGH
0.4
VCC - 0.6
V
IOUT = 1.6mA
V
IOUT = -1.0mA
Receiver Threshold to Drivers
Enabled (tONLINE)
200
µS
Figure 15
Receiver Positive or Negative
Threshold to STATUS HIGH
(tSTSH)
0.5
µS
Figure 15
Receiver Positive or Negative
Threshold to STATUS LOW
(tSTSL)
20
µS
Figure 15
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
3
© Copyright 2004 Sipex Corporation
SPECIFICATIONS (continued)
Unless otherwise noted, the following specifications apply for VCC = +3.0V to +5.5V with TAMB = TMIN to TMAX.
Typical values apply at VCC = +3.3V or +5.0V and TAMB = 25°C.
PARAMETER
MIN.
TYP.
MAX.
UNITS
CONDITIONS
120
240
kbps
Receiver Propagation Delay
tPHL
tPLH
0.3
0.3
µs
Receiver input to Receiver output, CL = 150pF
Receiver Output Enable Time
200
ns
Normal operation
Receiver Output Disable Time
200
ns
Normal operation
Driver Skew
100
500
ns
| tPHL - tPLH |, TAMB = 25oC
Receiver Skew
200
1000
ns
| tPHL - tPLH |
30
V/µs
TIMING CHARACTERISTICS
Maximum Data Rate
Transition-Region Slew Rate
RL = 3KΩ, CL = 1000pF, one driver active
VCC= 3.3V, RL = 3KΩ, TAMB = 25oC,
measurements taken from -3.0V to +3.0V or
+3.0V to -3.0V
TYPICAL PERFORMANCE CHARACTERISTICS
Unless otherwise noted, the following performance characteristics apply for VCC = +3.3V, 235Kbps data rate, all drivers
loaded with 3KΩ, 0.1µF charge pump capacitors, and TAMB = +25°C.
14
12
4
10
Vout+
Vout-
2
Slew Rate [V/µs]
Transmitter Output Voltage [V]
6
0
0
1000
500
1500
-2
8
6
+Slew
-Slew
4
2
-4
0
-6
0
Load Capacitance [pF]
500
1000
1500
Load Capacitance [pF]
2000
Figure 2. Slew Rate VS. Load Capacitance
Figure 1. Transmitter Output Voltage VS. Load
Capacitance
40
118KHz
60KHz
10KHz
Supply Current [mA]
35
30
25
20
15
10
5
0
0
500
1000
1500
Load Capacitance [pF]
2000
Figure 3. Supply Current VS. Load Capacitance when
Transmitting Data
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
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© Copyright 2004 Sipex Corporation
NAME
FUNCTION
PIN NO.
EN
Receiver Enable. Apply logic HIGH for normal operation.
Apply logic LOW to disable the receiver outputs (high-Z
state).
1
C1+
Positive terminal of the voltage doubler charge-pump
capacitor.
2
V+
Regulated +5.5V output generated by the charge pump.
3
C1-
Negative terminal of the voltage doubler charge-pump
capacitor.
4
C2+
Positive terminal of the inverting charge-pump capacitor.
5
C2-
Negative terminal of the inverting charge-pump capacitor.
6
V-
Regulated -5.5V output generated by the charge pump.
7
RS-232 receiver input.
8
TTL/CMOS receiver output.
9
TTL/CMOS Output indicating ONLINE and SHUTDOWN
status.
10
TTL/CMOS driver input.
11
Apply logic HIGH to override Auto-Online circuitry keeping
drivers active (SHUTDOWN must also be logic HIGH, refer
to Table 2).
12
RS-232 driver output.
13
Ground.
14
+3.0V to +5.5V supply voltage.
15
R1IN
R1OUT
STATUS
T1IN
ONLINE
T1OUT
GND
VCC
Apply logic LOW to shut down drivers and charge pump.
SHUTDOWN This overrides all Auto-Online circuitry and ONLINE (refer to
Table 2).
16
Table 1. Device Pin Description
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
5
© Copyright 2004 Sipex Corporation
EN
16 SHUTDOWN
1
C1+ 2
V+
3
C1-
4
C2+
15 VCC
14 GND
SP3221
13
T1OUT
5
12
ONLINE
C2-
6
11 T1IN
V-
7
10
STATUS
R1IN
8
9
R1OUT
Figure 4. SP32221E Pinout Configuration
C5
C1
+
+
VCC
15
0.1µF
VCC
2 C1+
3
0.1µF
C3
4 C15 C2+
C2
V+
+
V-
6 C2T1OUT 13
11 T1IN
9 R1OUT
TTL/CMOS
OUTPUTS
0.1µF
7
C4
0.1µF
TTL/CMOS
INPUTS
SP3221
+
R1IN
5KΩ
8
+
0.1µF
RS-232
OUTPUTS
RS-232
INPUTS
1 EN
12 ONLINE
VCC
TO POWER
MANAGEMENT
UNIT
16
SHUTDOWN
10 STATUS
GND
14
Figure 5. SP3221E Typical Operating Circuit
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
6
© Copyright 2004 Sipex Corporation
DESCRIPTION
Drivers
The SP3221E transceiver meets the EIA/
TIA-232 and ITU-T V.28/V.24 communication
protocols and can be implemented in batterypowered, portable, or hand-held applications
such as notebook or hand held computers. The
SP3221E 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 SP3221E device can operate
at a typical data rate of 240Kbps fully loaded.
The driver is 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. This
driver complies with the EIA-TIA-232F and all
previous RS-232 versions.
The driver typically can operate at a data rate
of 250Kbps. The driver can guarantee a data rate
of 250Kbps fully loaded with 3KΩ in
parallel with 1000pF, ensuring compatibility
with PC-to-PC communication software.
The SP3221E is a 1-driver/1-receiver device is
ideal for portable or hand-held applications and
power sensitive designs. The device features
Auto-Online circuitry which reduces the power
supply drain to a 1µA supply current. In many
portable or hand-held applications, an RS-232
cable can be disconnected when not in use.
Under these conditions, the internal charge pump
and the driver will be shut down. Otherwise, the
device automatically comes online. This feature
allows design engineers to address power saving
concerns without major design changes.
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.
The SP3221E driver can maintain high data
rates up to 240Kbps fully loaded. Figure 6
shows a loopback test circuit used to test the
RS-232 drivers. Figure 7 shows the test results
of the loopback circuit with the driver active at
250Kbps with typical RS-232 loads in parallel
with 1000pF capacitors. Figure 8 shows the test
results where the loaded driver was active at
235Kbps with an RS-232 receiver in parallel
with a 1000pF capacitor. A solid RS-232 data
transmission rate of 250Kbps provides
compatibility with many designs in personal
computer peripherals and LAN applications.
THEORY OF OPERATION
The SP3221E device is made up of four basic
circuit blocks: 1. Drivers, 2. Receivers,
3. the Sipex proprietary charge pump, and
4. Auto-Online circuitry.
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
7
© Copyright 2004 Sipex Corporation
+3V to +5V
DEVICE: SP3221E
SHUTDOWN
TXOUT
EN
C5
RXOUT
C1
+
+
19
VCC
0.1µF
2 C1+
V+
C3
0
0
High Z
Active
0
1
High Z
High Z
C2
1
0
Active
Active
TTL/CMOS
INPUTS
11 T1IN
1
1
Active
High Z
TTL/CMOS
OUTPUTS
9 R1OUT
Table 2. SHUTDOWN and EN Truth Tables
Note: In Auto-Online Mode where ONLINE = GND and
SHUTDOWN = VCC, the device will shut down if there is
no activity present at the Receiver inputs.
+
0.1µF
VCC
SP3221E
V-
0.1µF
7
C4
6 C2T1OUT
R1IN
+
0.1µF
13
8
5KΩ
1000pF
1 EN
20
14
To µP Supervisor
Circuit
11
SHUTDOWN
ONLINE
STATUS
Receivers
GND
18
The receiver converts ±5.0V EIA/TIA-232
levels to TTL or CMOS logic output levels. The
receiver has an inverting output that can be
disabled by using the EN pin.
Figure 6. Loopback Test Circuit for RS-232 Driver Data
Transmission Rates
Since receiver 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 300mV. This
ensures that the receiver is virtually immune to
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.
The receiver is active when the Auto-Online
circuitry is enabled or when in shutdown.
During the shutdown, the receiver will continue
to be active.
Driving EN to a logic HIGH forces the output of
the receiver into high-impedance.
[
T
]
[
T
T
]
T
T1 IN 1
T1 OUT 2
T1 OUT 2
T
T
T
T
R1 OUT 3
R1 OUT 3
Ch1 5.00V
Ch3 5.00V
Ch2 5.00V M 5.00µs Ch1
Ch1 5.00V
Ch3 5.00V
0V
Figure 7. Loopback Test Circuit Result at 250Kbps
(Driver Fully Loaded)
Date: 7/21/04
+
4 C15 C2+
T1 IN 1
3
0.1µF
Ch2 5.00V M 2.50µs Ch1
0V
Figure 8. Loopback Test Circuit result at 235Kbps
(Driver Fully Loaded)
SP3221E +3.0V to +5.5V RS-232 Transceiver
8
© Copyright 2004 Sipex Corporation
Charge Pump
Phase 3
— 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.
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
— 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. This oscillator controls the four phases
of the voltage shifting. A description of each
phase follows.
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.
Phase 1
— 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.
The clock rate for the charge pump typically
operates at 250kHz. The external capacitors can
be as low as 0.1µF with a 16V breakdown
voltage rating.
Phase 2
— 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 C 3. 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.
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
9
© Copyright 2004 Sipex Corporation
S
H
U
T
RECEIVER +2.7V
0V
RS-232 INPUT
VOLTAGES -2.7V
D
O
W
N
VCC
STATUS
0V
tSTSL
tSTSH
tONLINE
+5V
DRIVER
RS-232 OUTPUT
VOLTAGES
0V
-5V
Figure 9. Auto-Online Timing Waveforms
VCC = +5V
C4
+5V
C1
+
C2
–
–5V
+
–
–
+
VDD Storage Capacitor
+
–
VSS Storage Capacitor
C3
–5V
Figure 10. Charge Pump — Phase 1
VCC = +5V
C4
C1
+
–
C2
+
–
–
+
+
–
VDD Storage Capacitor
VSS Storage Capacitor
C3
–10V
Figure 11. Charge Pump — Phase 2
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
10
© Copyright 2004 Sipex Corporation
[
T
]
+6V
a) C2+
T
1
0V
2
2
0V
b) C2T
-6V
Ch1 2.00V Ch2 2.00V M 1.00µs Ch1 1.96V
Figure 12. Charge Pump Waveforms
VCC = +5V
C4
+5V
C1
+
C2
–
–5V
+
–
–
+
+
–
VDD Storage Capacitor
VSS Storage Capacitor
C3
–5V
Figure 13. Charge Pump — Phase 3
VCC = +5V
+10V
C4
+
C1
+
–
C2
–
+
–
–
+
VDD Storage Capacitor
VSS Storage Capacitor
C3
Figure 14. Charge Pump — Phase 4
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
11
© Copyright 2004 Sipex Corporation
RS-232 Cable
Connected?
SHUTDOWN
INPUT
ONLINE
INPUT
STATUS
OUTPUT
TRANSCEIVER
STATUS
TxOUT
YES
HIGH
-
HIGH
Normal
Operation
Active
NO
HIGH
HIGH
LOW
Normal
Operation
Active
NO
HIGH
LOW
LOW
Shutdown
(Auto-Online)
HiZ
YES
LOW
-
HIGH
Shutdown
HiZ
NO
LOW
-
LOW
Shutdown
HiZ
Table 3. Auto-Online Logic
NOTE: For proper ONLINE function the SP3221E and cable must be
connected to another RS232 Transceiver (3kΩ to 7kΩ load).
SP3221E
Cable unplugged
ONLINE
STATUS
Device enters low-power mode
automatically
STATUS forced low
SP321E
RS232 Device
Cable is connected to
RS-232 Reciever
ONLINE
STATUS
SP3221E comes ONLINE
automatically
STATUS Drives High
Figure 15. SP3221E AutoOnline Operation
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
12
© Copyright 2004 Sipex Corporation
Auto-Online Circuitry
Tying ONLINE and SHUTDOWN together
will bypass the Auto-Online circuitry so this
connection acts like a shutdown input pin.
The SP3221E device has an Auto-Online circuitry on board that saves power in the system
the device is designed into without changes to
the existing BIOS or operating system.
The SP3221E device incorporates an
Auto-Online circuit that automatically
enables itself when the cable is connected to
another RS232 device. Conversely, the AutoOnline circuit also disables most of the internal
circuitry when the cable is disconnected and
goes into a standby mode where the device
typically draws 1µA. This function is controlled
by the ONLINE pin. When this pin is tied to a
logic LOW, the Auto-Online function is active.
When the cable is disconnected, the receiver
inputs will be pulled down by its internal 5kΩ
resistors to ground. When ONLINE is HIGH,
the Auto-Online mode is disabled.
When the SP3221E driver or internal charge
pump are disabled, the supply current is reduced
to 1µA.
The Auto-Online mode can be overridden by the
SHUTDOWN pin. If this pin is a logic LOW,
the Auto-Online function will not operate
regardless of the logic state of the ONLINE pin.
Table 3 summarizes the logic of the Auto-Online
operating modes. The truth table logic of the driver
and receiver outputs can be found in Table 2.
The STATUS pin outputs a logic LOW signal
if the device is shutdown. This pin goes to a
logic HIGH when the external cable is connected
to another RS232 device.
When the SP3221E device is shutdown, 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 200µs.
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
13
© Copyright 2004 Sipex Corporation
normal usage. The transceiver IC receives most
of the ESD current when the ESD source is
applied to the connector pins. The test circuit for
IEC1000-4-2 is shown on Figure 18. There are
two methods within IEC1000-4-2, the Air
Discharge method and the Contact Discharge
method.
ESD TOLERANCE
The SP3221E 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 electrostatic
discharges and associated transients. The
improved ESD tolerance is at least +15kV
without damage nor latch-up.
With the Air Discharge Method, an ESD voltage
is applied to the equipment under test (EUT)
through air. This simulates an electrically charged
person ready to connect a cable onto the rear of
the system only to find an unpleasant zap just
before the person touches the back panel. The
high energy potential on the person discharges
through an arcing path to the rear panel of the
system before he or she even touches the system.
This energy, whether discharged directly or
through air, is predominantly a function of the
discharge current rather than the discharge
voltage. Variables with an air discharge such as
approach speed of the object carrying the ESD
potential to the system and humidity will tend to
change the discharge current. For example, the
rise time of the discharge current varies with the
approach speed.
There are different methods of ESD testing
applied:
a) MIL-STD-883, Method 3015.7
b) IEC1000-4-2 Air-Discharge
c) IEC1000-4-2 Direct Contact
The Human Body Model has been the generally
accepted ESD testing method for semiconductors.
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 electrostatic energy and
discharge it to an integrated circuit. The
simulation is performed by using a test model as
shown in Figure 17. This method will test the
IC’s capability to withstand an ESD transient
during normal handling such as in manufacturing
areas where the ICs tend to be handled frequently.
The Contact Discharge Method applies the ESD
current directly to the EUT. This method was
devised to reduce the unpredictability of the
ESD arc. The discharge current rise time is
constant since the energy is directly transferred
without the air-gap arc. In situations such as
hand held systems, the ESD charge can be directly
discharged to the equipment from a person already
holding the equipment. The current is transferred
on to the keypad or the serial port of the equipment
directly and then travels through the PCB and finally
to the IC.
The IEC-1000-4-2, formerly IEC801-2, is
generally used for testing ESD on equipment and
systems. For system manufacturers, they must
guarantee a certain amount of ESD protection
since the system itself is exposed to the outside
environment and human presence. The premise
with IEC1000-4-2 is that the system is required
to withstand an amount of static electricity when
ESD is applied to points and surfaces of the
equipment that are accessible to personnel during
R
RSS
R
RC
C
SW2
SW2
SW1
SW1
C
CSS
DC Power
Source
Device
Under
Test
Figure 17. ESD Test Circuit for Human Body Model
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
14
© Copyright 2004 Sipex Corporation
Contact-Discharge Module
R
RSS
R
RC
C
RV
SW2
SW1
Device
Under
Test
CSS
DC Power
Source
RS and RV add up to 330Ω for IEC1000-4-2.
Figure 18. ESD Test Circuit for IEC1000-4-2
i➙
The circuit model in Figures 17 and 18 represent
the typical ESD testing circuit used for all three
methods. The CS is initially charged with the DC
power supply when the first switch (SW1) is on.
Now that the capacitor is charged, the second
switch (SW2) is on while SW1 switches off. The
voltage stored in the capacitor is then applied
through RS, the current limiting resistor, onto the
device under test (DUT). In ESD tests, the SW2
switch is pulsed so that the device under test
receives a duration of voltage.
30A
15A
0A
For the Human Body Model, the current limiting
resistor (RS) and the source capacitor (CS) are
1.5kΩ an 100pF, respectively. For IEC-1000-42, the current limiting resistor (RS) and the source
capacitor (CS) are 330Ω an 150pF, respectively.
t=0ns
t=30ns
t➙
Figure 19. ESD Test Waveform for IEC1000-4-2
The higher CS value and lower RS value in the
IEC1000-4-2 model are more stringent than the
Human Body Model. The larger storage capacitor
injects a higher voltage to the test point when
SW2 is switched on. The lower current limiting
resistor increases the current charge onto the test
point.
DEVICE PIN
TESTED
HUMAN BODY
MODEL
Air Discharge
Driver Outputs
Receiver Inputs
±15kV
±15kV
±15kV
±15kV
IEC1000-4-2
Direct Contact
±8kV
±8kV
Level
4
4
Table 4. Transceiver ESD Tolerance Levels
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
15
© Copyright 2004 Sipex Corporation
PACKAGE: 16 PIN TSSOP
D
e
Ø2
E1
E
Seaing Plane
L
Ø3
L1
1
Ø1
DETAIL A
2
INDEX AREA
D x E1
2 2
SEE DETAIL “A”
A2
A
Seating Plane
A1
b
B
16 PIN TSSOP
JEDEC MO-153
(AB) Variation
Dimensions in (mm)
MIN
A
-
A1
0.05
B
NOM MAX
-
1.20
-
0.15
1.05
A2
0.80
1.00
b
0.19
-
0.30
c
0.09
-
0.20
D
4.90
5.00
b
5.10
C
E
E1
6.40 BSC
4.30
4.40
4.50
Section B-B
e
Ø1
0º
4º
8º
Ø2
12º REF
Ø3
12º REF
L
L1
Date: 7/21/04
0.65 BSC
0.45
0.60
0.75
16 PIN TSSOP
1.00 REF
SP3221E +3.0V to +5.5V RS-232 Transceiver
16
© Copyright 2004 Sipex Corporation
PACKAGE: 16 PIN SSOP
D
N
SEE DETAIL “A”
E
E1
1
2
INDEX AREA
D x E1
2 2
2 NX R R1
A
Gauge Plane
16 PIN SSOP
JEDEC MO-150
(AC) Variation
MIN
A1
0.05
-
A2
1.65
1.75
b
0.22
-
0.38
c
0.09
-
0.25
D
5.90
6.20
E
7.40
7.80
8.20
5.00
5.30
5.60
0.55
0.75
0.95
-
2.0
A2
1.85
A
Seating Plane
L1
Ø
Ø
DETAIL A
NOM MAX
-
L
A
L
L1
A
E1
Seaing Plane
Dimensions in (mm)
6.50
WITH LEAD FINISH
c
1.25 REF
0º
4º
A1
b
8º
BASE METAL
b
Section A-A
16 PIN SSOP
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
17
© Copyright 2004 Sipex Corporation
ORDERING INFORMATION
Part Number
Operating Temperature Range
Package Type
SP3221ECY ........... ...............................0°C to +70°C ........................................................... 16-pin TSSOP
SP3221ECY/TR ..... ...............................0°C to +70°C ........................................................... 16-pin TSSOP
SP3221ECA ........... ...............................0°C to +70°C ............................................................. 16-pin SSOP
SP3221ECA/TR ..... ...............................0°C to +70°C ............................................................. 16-pin SSOP
SP3221EEY ......... ...............................-40°C to +85°C .......................................................... 16-pin TSSOP
SP3221EEY/TR .... ...............................-40°C to +85°C .......................................................... 16-pin TSSOP
SP3221EEA ......... ...............................-40°C to +85°C ............................................................ 16-pin SSOP
SP3221EEA/TR .... ...............................-40°C to +85°C ............................................................ 16-pin SSOP
Available in lead free packaging. To order add "-L" suffix to part number.
Example: SP3221ECA/TR = standard; SP3221ECA-L/TR = lead free
/TR = Tape and Reel
Pack quantity is 1,500 for TSSOP and 2,500 for SSOP.
Corporation
ANALOG EXCELLENCE
Sipex Corporation
Headquarters and
Sales Office
233 South Hilliview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
e-mail: [email protected]
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.
Date: 7/21/04
SP3221E +3.0V to +5.5V RS-232 Transceiver
18
© Copyright 2004 Sipex Corporation