LMS202E
15KV ESD Rated, 5V Single Supply TIA/EIA-232 Dual
Transceivers
General Description
The LMS202E features two transmitters and two receivers
for RS-232 communication. It has a DC-to-DC converter that
permits the device to operate with only a single +5V power
supply. The on-chip DC-to-DC converter which utilizes four
external 0.1F capacitors to generate dual internal power
supplies for RS-232 compatible output levels.
The device meet EIA/TIA-232E and CCITT V.28 specifica-
tions up to 230kbits/sec. The LMS202E is available in a 16
pin narrow and wide SOIC package.
The transmitter outputs and receiver inputs have
15kV
electrostatic discharge (ESD) protection. The LMS202E sur-
vives a
15kV ESD event to the RS-232 input and output
pins when subjected according to Human Body Model or IEC
1000-4-2 (EN61000-4-2),air-gap specification. It survives a
8kV discharge when subjected to IEC 1000-4-2 (EN61000-
4-2), contact specification. This device is designed for use in
harsh environments where ESD is a concern.
Features
n
ESD protection for RS-232 I/O pins
--
15kV-IEC1000 4-2 (EN61000-4-2) Contact
Discharge
--
8kV-IEC1000 4-2 (EN61000-4-2) Air-Gap Discharge
--
15kV Human Body Model
n
Single +5V power supply
n
230 kbps data rate
n
On-board DC-to-DC converter
n
0.1F charge pump capacitors
n
Drop-in replacement to Maxim's MAX202E
Applications
n
POS equipment (Bar code reader)
n
Hand-held equipment
n
General purpose RS-232 communication
Connection Diagram and Typical Circuit
20048001
March 2003
LMS202E
15KV
ESD
Rated,
5V
Single
Supply
TIA/EIA-232
Dual
T
ransceivers
2003 National Semiconductor Corporation
DS200480
www.national.com
Pin Descriptions
Pin Number
Pin Name
Pin Function
1, 3
C1+, C1-
External capacitor connection pins. Recommended external capacitor C1 = 0.1F (6.3V)
2
V+
Positive supply for TIA/EIA-232E drivers. Recommended external capacitor C4 = 0.1F (6.3V)
4, 5
C2+, C2-
External capacitor connection pins. Recommended external capacitor C2 = 0.1F (16V)
6
V-
Negative supply for TIA/EIA-232E drivers. Recommended external capacitor C3 = 0.1F (16V)
7, 14
T1out, T2out
Transmitter output pins conform to TIA/EIA-232E levels. The typical transmitter output swing is
8V when loaded 3k
load to ground. The open-circuit output voltage swings from (V+ - 0.6V)
to V-
8,13
R1in, R2in
Receiver inputs accept TIA/EIA-232
9, 12
R1out and R2out Receiver output pins are TTL/CMOS compatible
10, 11
Tin1, Tin2
Transmitter input pins are TTL/CMOS compatible. Inputs of transmitter do not have pull-up
resistors. Connect all unused transmitter inputs to ground
15
GND
Ground pin
16
V
S
Power supply pin for the device, +5V (
10%)
Ordering Information
Package
Part Number
Package Marking
Transport Media
NSC Drawing
16-Pin SOIC
LMS202ECM
LMS202ECM
48 Units/Rail
M16A
LMS202ECMX
2.5k Units Tape and Reel
LMS202EIM
LMS202EIM
48 Units/Rail
LMS202EIMX
2.5k Units Tape and Reel
16-Pin Wide SOIC
LMS202ECMW
LMS202ECMW
45 Units/Rail
M16B
LMS202ECMWX
1.0k Units Tape and Reel
LMS202EIMW
LMS202EIMW
45 Units/Rail
LMS202EIMWX
1.0k Units Tape and Reel
LMS202E
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2
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
V
S
-0.3V to 6V
V+
(V
S
- 0.3V) to + 14V
V-
+0.3V to -14V
Driver Input Voltage, T
IN
-0.3V to (V+ +0.3V)
Receiver Input Voltage, R
IN
30V
Driver Output Voltage T
O
(V- -0.3V to (V+ + 0.3V)
Receiver Output Voltage R
O
-0.3 to (V
S
+ 0.3)
Short Circuit Duration, T
O
Continuous
ESD Rating
IEC 1000-4-2) (Note 7)
(Note 8)
Air-Gap Discharge
15kV
Contact Discharge
8kV
Human Body Model (Note 2)
(Note 8)
15kV
(Note 9)
2kV
ESD Rating (MM)
200V (Note 6) (Note 9)
Soldering Information
Infrared or Convection
235C
(20sec.)
Junction Temperature
150C
Storage Temperature Range
-65C to +150C
Operating Ratings
Supply Voltage V
S
4.5V to 5.5V
Ambient Temperature Range, T
A
Commercial (C)
0C to +70C
Industrial (I)
-40C to +85C
Package Thermal Resistance
(Note 3)
SO
71C/W
WSO
55C/W
Electrical Characteristics
Over recommended operating supply and temperature ranges unless otherwise specified C1 = C2 = C3 = C4 = Cbp = 0.1F
Symbol
Parameter
Conditions
Min
(Note 5)
Typ
Max
(Note 5)
Units
DC Characteristics
I
S
Supply Current
No Load, T
A
= 25C
1
7
mA
Logic
I
INPUT
Input Leakage Current
T
IN
= 0V to V
S
10
A
V
THL
Input Logic Theshold Low
T
IN
0.8
V
V
THH
Input Logic Theshold High
T
IN
2.0
V
V
OL
TTL/CMOS Output Voltage
Low
R
OUT
, I
OUT
= 3.2mA
0.4
V
V
OH
TTL/CMOS Output Voltage
High
R
OUT
, I
OUT
= -1.0mA
3.5
V
S
-0.1
V
RS-232 Receiver Inputs
V
RI
Receiver Input Voltage
Range
-30
+30
V
V
RTHL
Receiver Input Theshold
Low
V
S
= 5V, T
A
= 25C
0.8
1.4
V
V
RTHH
Receiver Input Theshold
High
V
S
= 5V, T
A
= 25C
2
2.4
V
V
HYST
Receiver Input Hysteresis
V
S
= 5V
0.2
0.6
1.0
V
R
I
Receiver Input Resistance
V
S
= 5V, T
A
= 25C
3
5
7
k
RS-232 Transmitter Outputs
V
O
Transmitter Output Voltage
Swing
All transmitters loaded with 3k
to GND
5
8
V
R
O
Output Resistance
V
S
= V+ = V- = 0V,
V
O
=
2V
300
I
OS
Output Short Circuit Current
11
60
mA
Timing Characteristics
DR
Maximum Data Rate
C
L
= 50pF to 1000pF,
R
L
= 3k
to 7k
230
kbps
LMS202E
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Electrical Characteristics
(Continued)
Over recommended operating supply and temperature ranges unless otherwise specified C1 = C2 = C3 = C4 = Cbp = 0.1F
Symbol
Parameter
Conditions
Min
(Note 5)
Typ
Max
(Note 5)
Units
T
RPLH
T
RPHL
Receiver Propagation Delay C
L
= 150pF
0.08
1
s
T
DPLH
T
DPHL
Transmitter Propagation
Delay
R
L
= 3k
, C
L
= 2500pF
All transmitters loaded
2.4
s
V
SLEW
Transition Region Slew Rate T
A
= 25C, V
S
= 5V
C
L
= 50pF to 1000pF, R
L
= 3k
to 7k
Measured from +3V to -3V or vice versa
3
6
30
V/s
ESD Performance: Transmitter Outputs and Receiver Inputs
ESD Rating
Human Body Model
15
kV
IEC 1000-4-2, Contact
8
IEC 1000-4-2, Air-gap
15
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics.
Note 2: Human Body Model, 1.5k
in series with 100pF
Note 3: The maximum power dissipation is a function of T
J(MAX),
JA,
and T
A.
The maximum allowable power dissipation at any ambient temperature is P
D
=
(T
J(MAX)
- T
A
)/
JA.
All numbers apply for packages soldered directly onto a PC board.
Note 4: Typical Values represent the most likely parametric norm.
Note 5: All limits are guaranteed by testing or statistical analysis
Note 6: Machine model, 0
in series with 200pF
Note 7: IEC 1000-4-2, 330
in series with 150pF
Note 8: ESD rating applies to pins 7,8 13 and 14
Note 9: ESD rating applies to pins 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 15 and 16
LMS202E
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Typical Characteristics
Transmitter Output High Voltage vs. Load Capacitance
Transmitter Slew Rate vs. Load Capacitance
20048002
20048003
Application Information
CAPACITOR SELECTION
The recommended capacitors are 0.1F. However, larger
capacitors for the charge pump may be used to minimized
ripples on V+ and V- pins.
POWER SUPPLY DECOUPLING
In some applications that are sensitive to power supply noise
from the charge pump, place a decoupling capacitor, Cbp,
from V
S
to GND. Use at least a 0.1F capacitor or the same
size as the charge pump capacitors (C1 - C4).
CHARGED PUMP
The dual internal charged-pump provides the
10V to the to
transmitters. Using capacitor C1, the charge pump converts
+5V to +10V then stores the +10V in capacitor C3. The
charge pump uses capacitor C2 to invert the +10V to -10V.
The -10V is then stored in capacitor C4.
ELECTROSTATIC DISCHARGE PROTECTION
ESD protection has been placed at all pins to protect the
device from ESD. All pins except for the transmitter output
pins (pins 7 and 14) and receiver input pins (pins 8 and 13)
have a ESD rating of 2kV Human Body Model (HBM) and
200V Machine Model (MM). The RS-232 bus pins (pins 7, 8,
13 and 14) have a more robust ESD protection. The RS-232
bus pins have a ESD rating of 15kV HBM and IEC 1000-4-2,
air-gap. In addition the bus pins meet an ESD rating of 8kV
with IEC 1000-4-2, contact. The ESD structures can with-
stand a high ESD event under the following conditions:
powered-on, powered-off, and Input connected to high and
low with outputs unloaded.
HUMAN BODY MODEL
The Human Body Model is an ESD testing standard, defined
in Mil-STD-883C method 3015.7. It simulates a human dis-
charging an ESD charge to the IC device. The rise time is
approximately 10 ns and decay time is approximately 150
ns. The waveform is obtained by discharging 2kV volts ca-
pacitor through a resistor, R2 = 1.5 k
. The peak current is
approximately 1.33A.
20048004
FIGURE 1. HBM ESD Test Model
20048005
FIGURE 2. HBM Waveform
LMS202E
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