Discrete transistor
From Wikipedia, the free encyclopedia
Discrete transistors are transistors that are individually packaged.
The two main categories of packaging are through-hole (or leaded), and surface-mount, also known as surface mount device (SMD).
Transistor packages are made of glass, metal, ceramic or plastic. The package often dictates the power rating and frequency characteristics. Power transistors have large packages that can be clamped to heat sinks for enhanced cooling. Additionally, most power transistors have the collector or drain physically connected to the metal can/metal plate. At the other extreme, some surface-mount "microwave" transistors are as small as grains of sand.
Often a given transistor type is available in different packages. Transistor packages are mainly standardized, but the assignment of a transistor's functions to the terminals is not: different transistor types can assign different functions to the package's terminals. Even for the same transistor type the terminal assignment can vary (normally indicated by a suffix letter to the part number- i.e. BC212L and BC212K).
[edit] See also
[edit] External links to datasheets
A wide range of transistors has been available since the 1960s and manufacturers continually introduce improved types. A few examples from the main families are noted below. Unless otherwise stated, all types are made from silicon semiconductor. Complementary pairs are shown as NPN/PNP or N/P channel. Links go to manufacturer datasheets, which are in PDF format. (On some datasheets the accuracy of the stated transistor category is a matter of debate.)
- 2N3904/2N3906, BC182/BC212 and BC546/BC556: Ubiquitous, BJT, general-purpose, low-power, complementary pairs. They have plastic cases and cost roughly ten cents U.S. in small quantities, making them popular with hobbyists.
- AF107: Germanium, 0.5 watt, 250 MHz PNP BJT.
- BFP183: Low power, 8 GHz microwave NPN BJT.
- LM394: "supermatch pair", with two NPN BJTs on a single substrate.
- 2N2219A/2N2905A: BJT, general purpose, medium power, complementary pair. With metal cases they are rated at about one watt.
- 2N3055/MJ2955: For years, the venerable NPN 2N3055 has been the "standard" power transistor. Its complement, the PNP MJ2955 arrived later. These 1 MHz, 15 A, 60 V, 115 W BJTs are used in audio power amplifiers, power supplies, and control.
- 2SC3281/2SA1302: Made by Toshiba, these BJTs have low-distortion characteristics and are used in high-power audio amplifiers. They have been widely counterfeited[1].
- BU508: NPN, 1500 V power BJT. Designed for television horizontal deflection, its high voltage capability also makes it suitable for use in ignition systems.
- MJ11012/MJ11015: 30 A, 120 V, 200 W, high power Darlington complementary pair BJTs. Used in audio amplifiers, control, and power switching.
- BSP296/BSP171: IGFET (enhancement mode), medium power, near complementary pair. Used for logic level conversion and driving power transistors in amplifiers.
- IRF3710/IRF5210: IGFET (enhancement mode), 40 A, 100 V, 200 W, near complementary pair. For high-power amplifiers and power switches, especially in automobiles.
[edit] External links
- The CK722 Museum. Website devoted to the "classic" hobbyist germanium transistor
- Jerry Russell's Transistor Cross Reference Database.
- The DatasheetArchive. Searchable database of transistor specifications and datasheets.
