small outline transistor (transistor package) (SOT)
The SOT or SO package(Small Outline Transistor) is the standard package for diodes and transistors. It was developed as early as the 1970s for SMT technology and used in consumer electronics.
Under the name Small Outline Integrated Circuit( SOIC), the SOT design is also used for integrated circuits( IC). Over the years, the need for smaller IC and transistor packages has become more urgent, so the SOT package is also available in miniaturized form as SOT-23.
The SOT-23 package, renamed TO-236 by JEDEC, is only 1.3 mm wide, 3.0 mm long and 1.0 mm thick. The spacing of the pins is 1.9 mm. The dice contained in the SOT-23 package have an area of 0.75 qmm. One such SOT-23 can dissipate a power of 200 mW. The smallest SOT packages are only 0.8 mm wide, 1.6 mm long and 0.7 mm thick, and the pin spacing is 1.0 mm.
Ideal for small- signal transistors, SOT-23 packages can also contain analog circuits for voltage stabilizers, line drivers, receivers and receivers, LED drivers, thermostats, etc.
SOT packages come in a wide variety of sizes, the smallest have 3, 5, 6 and 8 pins.