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,[1] also manufacturers offer the nearly identical thin small outline transistor (TSOT) package, where lower height is important.[2][3][4][5]
SOT23-3, SOT323, SOT416
The SOT23-3 package is very popular and a common package for transistors, and is also used for diodes and voltage regulators.[1]
SOT54 is an alternate designation for the JEDEC TO-92 package.[23]
SOT143, SOT343
SOT143 (TO253), SOT343
Dimensions (mm)
SOT143
SOT343
A
B
C
D
F
G
1.78
1.2
H
J
K
L
R
S
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.
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.[25]
^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. 1: 264–270. doi:10.1109/PEDS.1995.404911. ISBN0-7803-2423-4.
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.