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Robert Zaccaria

#13122

Marking Codes | 4 January, 1999

I would like to know if it exist a croos reference book for marking code on smt device? I'm fixing a unit now and try to know what are the following devices: The look like transistors and are mark like that "8A" "C1HBB" "MN13"

Thank's, any help will be appreciate.

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K Gossman

#13123

Re: Marking Codes | 5 January, 1999

| I would like to know if it exist a croos reference book for marking code on smt device? | I'm fixing a unit now and try to know what are the following devices: | The look like transistors and are mark like that "8A" | "C1HBB" | "MN13" | | Thank's, any help will be appreciate. | Do you know who the supplier of the part is? Different suppliers have different ways of marking parts. Not all of them do it the same. If you know the supplier, you can check their web page, they should have a code there.

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Dave f

#13124

Re: Marking Codes | 5 January, 1999

| I would like to know if it exist a croos reference book for marking code on smt device? | I'm fixing a unit now and try to know what are the following devices: | The look like transistors and are mark like that "8A" | "C1HBB" | "MN13" | | Thank's, any help will be appreciate. | Prepared by mark-r@snow_white.ee.man.ac.uk

A frequently asked question is "I have a transistor marked ..., what type is it?". In order to help answer these problems I have compiled a description of the three major transistor marking codes. We are lucky with transistors that, apart from a few oddities which I'll talk about later, most markings follow one of these codes. ICs are more tricky as you're often dealing with custom chips or mask programmed devices with manufacturers individual codes. A quick hint though: always look for known numbers (e.g., 723, 6502, 2764) etc between the suffix and prefix, and beware of the date code.

Right, back to transistors. The three standard transistor marking schemes are:

1. Joint Electron Device Engineering Council (JEDEC). These take the form:

Marking Notation Digit First digit is one less than the number of legs, 2 for transistors, except for 4N and 5N which are reserved for optocouplers. Letter Always 'N' Serial number Runs from 100 to 9999 and tell nothing about the transistor except its approximate time of introduction. [suffix] [Optional suffix] indicates the gain (hfe) group of the device: A = low gain B = medium gain C = high gain No suffix = any gain.

See the data sheet for the actual gain spread and groupings. The reason for gain grouping is that the low gain devices are fractionally cheaper than the high gain devices, resulting in savings for high volume users.

Examples- 2N3819, 2N2221A, 2N904.

2. Japanese Industrial Standard (JIS). These take the form:

Marking Notation Digit First digit is one less than the number of legs, 2 for transistors, except for 4N and 5N which are reserved for optocouplers. Two letters The letters indicate the application area and flavor of the device accordingto the following code:SA: PNP HF transistor SB: PNP AF transistorSC: NPN HF transistor SD: NPN AF transistorSE: Diode SF: ThyristorsSG: Gunn devices SH: UJTSJ: P-channel FET/MOSFET SK: N-channel FET/MOSFETSM: Triac SQ: LEDSR: Rectifier SS: Signal diodesST: Avalanche diodes SV: VaricapsSZ: Zener diodes Serial number Runs from 10 to 9999 and tells nothing about the transistor except its approximate time of introduction. [suffix] [Optional suffix] indicates that the type is approved for use by various Japanese organizations.

NOTE. since the code for transistors always begins with 2S, it is sometimes (more often than not is seems) omitted so, for example, a 2SC733 would be marked C 733.

Examples- 2SA1187, 2SB646, 2SC733.

3. Pro-electron. These take the form:

Marking Notation Letter The first letter indicates the material: A = Germanium (Ge) B = Silicon (Si) C = Gallium Arsinide (GaAs) R = compound materials.Needless to say the biggest majority of transistors begin with a B. Letter The second letter indicates the device application:A: Diode RF N: OptocouplerB: Variac P: Radiation sensitive deviceC: transistor, AF, small signal Q: Radiation producing deviceD: transistor, AF, power R: Thyristor, Low powerE: Tunnel diode T Thyristor, PowerF: transistor, HF, small signal U: Transistor, power, switchingK: Hall effect device Y: RectifierL: Transistor, HF, power Z: Zener, or voltage regulator diode [Letter] [Optional third letter] indicates that the device is intended for industrial or professional rather than commercial applications. It is usually a W,X,Y or Z. Serial number Runs from 100 to 9999 and tell nothing about the transistor except its approximate time of introduction. [suffix] [Optional suffix] indicates the gain grouping, as for JEDEC.

Examples- BC108A, BAW68, BF239, BFY51.

Apart from JEDEC, JIS and Pro-electron, manufacturers often introduce their own types, for commercial reasons (i.e., to get their name into the code) or to emphasize that the range belongs to a specialist application. Common brand specific prefixes are:

MJ: Motorola power, metal case MJE: Motorola power, plastic case MPS: Motorola low power, plastic case MRF: Motorola HF, VHF and microwave transistor RCA: RCA RCS: RCS TIP: Texas Instruments power transistor (plastic case) TIPL: TI planar power transistor TIS: TI small signal transistor (plastic case) ZT: Ferranti ZTX: Ferranti

Examples- ZTX302, TIP31A, MJE3055, TIS43.

Many manufacturers also make custom parts for large volume OEM use. These parts are optimized for use in a given part of a given circuit. They usually just have a manufacturers stamp and an untraceable number. Often when a company goes bankrupt, or has surplus at the end of a production run, these transistors find their way into hobbyist bargain packs. There is no way that you can trace data on these devices, so they are only suitable as LED drivers, buffers, etc., where the actual parameters are not important. Check carefully before buying.

Transistor cross reference: http://www.ee.washington.edu/eeca/parts/cross.html IC Manufacturer logo identification: http://www.amc.com/chipdir/c/logo.htm

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H.J.Zwier

#13125

Re: Marking Codes | 10 January, 2000

Hi Robert,

Try looking at www.marsport.demon.co.uk/smd/ This site contains a list of html files with all marking codes known at this moment.

Your example of a transistor with marking code 8A can be a 3V3 zener diode or a npn general purpose transistor in SOT23 or SOT323 package. All 3 are by Motorola, so you'll have to look there for the exact marking code.

Regards,

Harm-Jelle Zwier Senior design engineer at Artesyn Technologies, Etten-Leur, the Netherlands

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