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Family of discrete surface mount transistors
Size comparison of transistor packages. Two surface-mount packages, SOT23 and SOT223, are shown next to through-hole packages
A small outline transistor (SOT) is a family of small footprint, discrete surface mounttransistor commonly used in consumer electronics. The most common SOT are SOT23 variations,. SOT23-5 differs from SOT23 in a wider body of 1.6 mm (0.063 in) instead of 1.3 mm (0.051 in). Also, manufacturers offer the nearly identical thin small outline transistor (TSOT/TSOP) package, where lower height is important.
SOT23, SOT323, SOT416
The SOT23 package is very popular and a common package for transistors, as well as diodes and voltage regulators.
SOT54 is an alternate designation for the JEDEC TO-92 package.
SOT23-4, SOT143, SOT343
SOT23-4, SOT143 (TO253), SOT343
Dimensions (mm)
SOT143
SOT343
A
2.90 ±0.10
2.00 - 2.20
B
1.30 ±0.10
1.150 - 1.350
C
0.900 - 1.100
D
0.400 +0.110 -0.030
0.250 - 0.400
F
0.800 +0.130 -0.030
0.350 - 0.500
G
1.92 +0.11 -0.14
1.200 - 1.400
H
0.05 +0.05 -0.037
0.000 - 0.100
J
0.11 +0.07 -0.025
0.080 - 0.150
K
0.89 - 1.00
0.525
L
R
S
2.38 ±0.10
2.150 - 2.450
SOT490
SOT490 (SOT523F, SC89, EMT3F)
Dimensions (mm)
A
B
C
D
G
0.5
J
K
S
L
1.0
SOT89-3
The SOT89-3 electrically only has three leads (contact/pin). The wide lead (tab) is physically part of the middle lead on the other side of the package. Some call this package a SOT89-4, since it visually appears to have four leads when looking down at the part.
SOT89-3 (TO243AA, SC62, MPT3)
Dimensions (mm)
A
4.5
B
2.5
C
1.5 ± 0.1
D
E
1.6
F
G
1.5
J
K
S
L
3
SOT89-5
The SOT89-5 electrically only has five leads (contact/pin). The middle lead is physically part of the middle lead on the other side of the package. Some call this package a SOT89-6, since it visually appears to have six leads when looking down at the part.
SOT89-5
Dimensions (mm)
A
4.6
B
2.6
C
1.6
D
E
F
G
1.5
H
J
K
S
L
SOT223 (SOT223-4)
The SOT223-4 package is a popular package for voltage regulators. It was introduced by Philips.
SOT223-4 (SC73, TO261AA)
Dimensions (mm)
Min
Typ
Max
A
1.80
A1
0.02
b
0.60
0.70
0.80
b2
2.90
3.00
3.10
c
0.24
0.26
0.32
D
6.30
6.50
6.70
e
2.3
e1
4.6
E
6.70
7.00
7.30
E1
3.30
3.50
3.70
SOT223-5
The SOT223-5 package is a popular package for voltage regulators.
SOT223-5
Dimensions (mm)
Min
Typ
Max
A
1.8
A1
0.02
0.04
0.10
A2
1.55
1.65
A3
0.87
0.91
b
0.41
0.46
0.51
b2
2.95
3.00
3.05
C
0.24
0.32
D
6.45
6.50
6.55
E
6.86
7.00
7.26
E1
3.45
3.50
3.55
e
1.27
e1
5.08
L
0.91
1.14
SOT223-8
The SOT223-8 package is a popular package for bridged quad transistors.
"SOT457 Package information" (PDF). NXP. 2018-05-05. Retrieved 2022-05-25. plastic, surface-mounted package (TSOP6); 6 leads; 0.95 mm pitch; 2.9 mm x 1.5 mm x 1 mm body
"SOT363 Package information" (PDF). NXP. 2018-05-09. Retrieved 2021-09-07. plastic, surface-mounted package; 6 leads; 0.65 mm pitch; 2mm x 1.25 mm x 0.95 mm body
Hollander, Dave (1995). "Packaging trends and mounting techniques for power surface mount components". Proceedings of 1995 International Conference on Power Electronics and Drive Systems. PEDS 95. Vol. 1. pp. 264–270. doi:10.1109/PEDS.1995.404911. ISBN0-7803-2423-4. S2CID109636238.
It is relatively common to find packages that contain other components than their designated ones, such as diodes or voltage regulators in transistor packages, etc.
