A small outline transistor (SOT) is a family of small footprint, discrete surface mount transistor commonly used in consumer electronics. The most common SOT are SOT23 variations,. SOT23-5 differs from SOT23 in a wider body of instead of . Also, manufacturers offer the nearly identical thin small outline transistor (TSOT/TSOP) package, where lower height is important.
The SOT23-3 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.
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.
The SOT223-4 package is a popular package for voltage regulators. It was introduced by Philips.
The SOT223-5 package is a popular package for voltage regulators.
The SOT223-8 package is a popular package for bridged quad transistors.