SOT-23 Plastic-Encapsulate ESD Protection Diodes
DN:T20401A0
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Asymmetrical TVS Diode for
Extended Common-Mode RS-485
SM712
Schematic & Pin Configuration
Applications
Protection of RS-485 transceivers with extended
common-mode range
Mechanical Characteristics
Package: SOT-23
Flammability Rating: UL 94V-0
Features
Transient protection for asymmetrical data lines to
IEC61000-4-2 (ESD) ±15kV (air), ±8kV (contact)
IEC61000-4-4 (EFT) 40A (5/50ns)
Protects two +12V to -7V lines
Low capacitance
Circuit Diagram
High temperature soldering guaranted:
260℃/10s
Security systems
Automatic Teller Machines
HFC systems
DESCRIPTION
The SM712 transient voltage suppressor (TVS) diode is designed for asymmetrical (12V to -7V)
protection in multi-point data transmission standard RS-485 applications. The SM712 may be used to
protect devices from transient voltages resulting from electrostatic discharge (ESD), electrical fast
transients (FET), and lightning.
The SM712 features 400 Watts (tp=8/20μs) of power handling capability to accommodate the higher
transient voltage levels which may be expected in extended common mode applications. This provides
higher equipment reliability and eliminates the “ guess work” required when using zener diodes that are
not rated to handle such transient conditions.
Low leakage current
Low clamping voltage
Meets MSL 1 Requirements
Marking: 712 or C72
Networks
The integrated design aids in reducing voltage over-shoot associated with trace inductance. The low
clamping voltage of the SM712 minimizes the stress on the protected transceiver. The SOT-23 package
allows flexibility in the design of “crowed” circuit boards.
SOT23 (Top View)
1
2
3
Solid-state silicon avalanche technology
IEC61000-4-5 (Lightning) 12A (8/20μs)
400 Watts Peak Pulse Power per (8/20μs)
Packaging: Tape and Reel
12V 12V
7V 7V
1
2
3GND
I/O 1
I/O 2
SM712
Terminal: Matte tin plated.
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The above data are for reference only.
E
lectrical
C
haracteristics
(T
A
=25°C unless otherwise specified)
Rev:2020A0
Absolute Maximum Ratings (T
A
=25°C unless otherwise specified)
Parameter Symbol Value Unit
ESD per IEC 61000−4−2 (Air)
ESD per IEC 61000−4−2 (Contact)
VESD
± 15
± 8
KV
Operating Temperature
T
OPT
−55 to +150
Lead Solder Temperature – Maximum (10 Second
Duration)
°C
T
L
260(10 sec.)
°C
Storage Temperature
TSTG
−55 to +150
°C
W
P
PP
400
Peak Pulse Power(8/20us )
A
I
PP
17
Peak Pulse Current(8/20us)
Pin 1 to 3 and
Pin 2 to 3
(12V) TVS
Pin 3 to 1 and
Pin 3 to 2
(7V TVS)
bol ParameSymbolm Test Condition
Min Typ Max Mini Max
Units
V
RWM
Reverse Working
Voltage
Pin 3 to 1 or
Pin 2 to 1
12
7
V
V
BR
Reverse
Breakdown Voltage
I
T
= 1mA 13.3 7.5 V
I
R
Reverse Leakage
Current
V
R
= V
RWM
1 20
μ
A
V
C1
Clamping Voltage 1
I
PP
= 5A,
t
p
= 8/20μs
20 10
V
V
C2
Clamping Voltage 2
I
PP
= 17A,
t
p
= 8/20μs
26
12
V
C
J1
Junction
Capacitance 1
V
R
= 0V,
f = 1MHz
75
75
pF
C
J2
Junction
Capacitance 2
V
R
= V
RWM
,
f = 1MHz
45 45
pF
Typ
Asymmetrical TVS Diode for
Extended Common-Mode RS-485
SM712