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SM2T series
April 2002 - Ed: 1A
Transient Voltage Suppressor: TRANSIL TM
The SM2T series are Transil diodes designed specifically
for portable equipment and miniaturized electronics de-
vices subject to ESD transient overvoltages.
Fully compatible with pick and place equipment and
inspectable soldering joints.
DESCRIPTION
K
A
DO-216AA
(ST mite)
Symbol
Parameter
Value
Unit
P
PP
Peak pulse power dissipation (see note 1)
Tj initial = Tamb
200
W
P
Power dissipation on infinitive heatsink
Tamb = 100C
2.5
W
I
FSM
Non repetitive surge peak forward current
tp = 10 ms
Tj initial = Tamb
25
A
T
stg
Tj
Storage temperature range
Maximum operating junction temperature
- 65 to + 175
150
C
TL
Lead solder temperature (10 seconds duration)
260
C
Note 1: 10/1000 s pulse waveform.
ABSOLUTE RATINGS (Tamb = 25C)
s
High Peak pulse power:
200 W (10/1000 s )
1000 W ( 8/20 s)
s
Stand-off voltage range 5 to 24V
s
Unidirectional types
s
Low clamping factor V
CL
/V
BR
s
Fast response time
s
1.0mm overall component height
FEATURES AND BENEFITS
Symbol
Parameter
Value
Unit
Rth (j-t)
Junction to tab
20
C/W
Rth (j-a)
Junction to ambient on PCB with recommended pad layout
250
C/W
THERMAL RESISTANCES
SM2T series
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Types
I
RM
max @ V
RM
V
BR
min @ I
R
V
CL
max @ I
PP
Note 1
T max
10-4/C
C typ
at 0V
SM2T6V8A
50A
5V
6.4V
10 mA
9.2V
19.6A
5.7
1600pF
SM2T14A
1A
12V
13.3V
1 mA
19.9V
9.0A
8.3
650pF
SM2T18A
1A
16V
17.1V
1 mA
26V
7A
8.8
500pF
SM2T27A
1A
24V
25.7V
1 mA
38.9V
4.6A
9.6
350pF
Note 1: 10/1000s pulse waveform.
1.E+01
1.E+02
1.E+03
1.E+04
0.01
0.10
1.00
10.00
t (ms)
P
T
j
initial = 25C
P (W)
PP
Fig. 1: Peak pulse power versus exponential pulse dura-
tion.
0
10
20
30
40
50
60
70
80
90
100
110
0
25
50
75
100
125
150
175
Tj(C)
%
Fig. 2: Relative variation of peak pulse power versus initial
junction temperature.
Symbol
Parameter
V
RM
Stand-off voltage
V
BR
Breakdown voltage
V
CL
Clamping voltage
I
RM
Leakage current @ V
RM
I
PP
Peak pulse current
T
Voltage temperature coefficient
ELECTRICAL CHARACTERISTICS (Tamb = 25C)
I
I F
V F
V
VCL
VBR
VRM
I PP
I RM
V
SM2T series
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1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
0
25
50
75
100
125
150
Tj(C)
V
R
=V
RM
I (nA)
R
Fig. 6: Reverse leakage current versus junction tempera-
ture (typical values).
0
50
100
150
200
250
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
S(cm)
Rth(j-a)(C/W)
Fig. 5: Thermal resistance junction to ambient versus
copper surface under tab.
0.1
1.0
10.0
100.0
0
5
10
15
20
25
30
35
40
45
V (V)
CL
8/20s
T
j
initial =25C
10/1000s
SM2T6V8A
SM2T14A
SM2T18A
SM2T27A
I (A)
PP
Fig. 7: Clamping voltage versus peak pulse current (maxi-
mum values).
10
100
1000
10000
1
10
100
V (V)
R
F=1MHz
V
osc
=30mV
RMS
T
j
=25C
SM2T6V8A
SM2T14A
SM2T18A
SM2T27A
C(pF)
Fig. 8: Junction capacitance versus reverse voltage ap-
plied (typical values).
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0
25
50
75
100
125
150
Tamb(C)
Tamb = Ttab
Printed circuit board FR4,
recommended pad layout
P(W)
Fig. 3: Average power dissipation versus ambient tem-
perature.
0.1
1.0
10.0
100.0
1000.0
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
t (s)
P
S=2cm
S=0.135cm
Zth(j-a)(C/W)
Fig. 4: Variation of thermal impedance junction to ambient
versus pulse duration.
SM2T series
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PACKAGE MECHANICAL DATA
DO216-AA (ST mite)
C
L2
L
A1
R1
R
0 to 6
b
H
b2
D
L3
A
E
REF.
DIMENSIONS
Millimeters
Inches
Min.
Typ.
Max.
Min.
Typ.
Max.
A
0.85
1.00
1.15
0.033
0.039
0.045
A1
0.10
0.004
b
0.40
0.65
0.016
0.025
b2
0.70
1.00
0.027
0.039
c
0.10
0.25
0.004
0.010
D
1.75
1.90
2.05
0.069
0.007
0.081
E
1.75
1.90
2.05
0.069
0.007
0.081
H
3.60
3.75
3.90
0.142
0.148
0.154
L
0.50
0.63
0.80
0.047
0.025
0.031
L2
1.20
1.35
1.50
0.047
0.053
0.059
L3
0.50 ref
0.019 ref
R
0.07
0.003
R1
0.07
0.003
Note: The anode is connected to the longer tab
The cathode is connected to the shorter tab (heatsink)
2.67
2.54
0.762
1.27
0.635
RECOMMENDED LAYOUT
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
0.0
0.5
1.0
1.5
2.0
2.5
3.0
VFM(V)
T
j
=25C
T
j
=150C
IFM(A)
Fig. 9: Forward voltage drop versus forward current (typi-
cal values).
SM2T series
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use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by
implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to
change without notice. This publication supersedes and replaces all information previously supplied.
STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written ap-
proval of STMicroelectronics.
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2002 STMicroelectronics - Printed in Italy - All rights reserved.
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Ordering type
Marking
Package
Weight
Base qty
Delivery mode
SM2T6V8A
MUA
ST mite
15.5 mg
12000
Tape & reel
SM2T14A
MUE
ST mite
15.5 mg
12000
Tape & reel
SM2T18A
MUG
ST mite
15.5 mg
12000
Tape & reel
SM2T27A
MUJ
ST mite
15.5 mg
12000
Tape & reel
OTHER INFORMATION
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