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The Surface Mount Device Code Book

© R P Blackwell GM4PMK

A marsport publication!


SMD devices are, by their very nature, too small to carry conventional semiconductor type numbers. Instead, a somewhat arbitrary coding system has grown up, where the device package carries a simple two- or three-character ID code. Identifying the manufacturers' type number of an SMD device from the package code can be a difficult task, involving combing through many different databooks. This HTML book is designed to provide an easy means of device identification. It lists over 3,500 device codes in alphabetical order, together with type numbers, device characteristics or equivalents and pinout information. Sometimes I'm asked to put IC information in the codebook. There is some information about ICs - but first and foremost the codebook is intended for discrete devices. Some ICs have been included, usually these are 3/4 pin devices or RF circuits I'm interested in.


The home of GM4PMK's SMD codebook is here - and it's only here you'll get the most up-to-date information as it's updated often........ There are a number of other copies of this codebook on the Net, of varying ages. Some are translations with my permission, some are just straight rip-offs. None of them will be as up to date as the original.

How to use the SMD Codebook

To identify a particular SMD device, first identify the package style and note the ID code printed on the device. Now look up the code in the alphanumeric listing which forms the main part of this book by clicking on the first character shown in the left-hand frame. A scrollable page of data will appear in the main frame.
Unfortunately, each device code is not necessarily unique. For example a device coded 1A might be either a BC846A or a FMMT3904. Even the same manufacturer may use the same code for different devices! If there is more than one entry, use the package style to differentiate between devices with the same ID code.

Identifying the package is not always easy - measuring the package dimensions may help; and the codebook has some information about these.

This compilation has been collected from manufacturers' data and other sources of SMD device ID codes, pinout and leaded device equivalent information. The entries under the Manufacturer column are not intended to be comprehensive; rather they are intended to provide help on locating sources of more detailed information if you require it.


When you have looked up a device, the Base letter will guide you to a pin-out diagram. Note that some bases have marks to show the correct orientations, on others, one or more 'pins' may be a different size or shape. Some packages have nothing at all - in that case the device is shown such that the ID code is the right way up.

ID Code Variations

Many manufacturers use an extra letter as their own identification code, or to show the country of manufacture. If the device is from Philips/NXP it will sometimes have a lower case 'p' or sometimes 't' added to the code; some manufacturers have used a symbol or lower case letter to indicate the country of manufacture. These have been ignored in the alphabetical ordering. For example 'Z-S' and 'ZtS ' are both 2PC4081Q devices made by Philips; the first made in Hong Kong and the second in Malaysia; they appear in the codebook classified under ZS. Siemens devices usually have a lower case 's'. Note that these prefix/suffix letters are always shown in lower case.

To save table space, often only ONE variant from each manufacturer will appear in the table.

Philips/NXP have used -, t, p and w to An example, if you have a device with the code 1At, look up 1Ap. Many recent Motorola devices have a small superscript letter after the device code, such as SAC. This smaller letter is merely a month of manufacture code. Many devices from Rohm Semiconductors which start with G have direct equivalents found in the rest of the code. For example GD1 is the same as D1 which is a BCW31.

Note that p6A (for example) is different from 6Ap. The position of the 'p' is important! In this case, p6A is a jfet, and 6Ap a bipolar transistor.

You'll find both of these in the '6' page though - in other words these lower case prefixes or suffixes are ignored for indexing purposes, but critical to identifying the device.

Some devices have a single coloured letter (usually on extremely small diode packages). Colour, if significant, is shown in small type after the code letter.

An 'L' or 'W' suffix usually indicates a low-profile package, such as an SOT323 or SC70.

A separate letter number group, often smaller and/or in a different orientation, is often used as a date code. To assist in identification, this is sometimes entered in the tables as x (lower case) as in '4Px' - device code 4P with a date code.

Reverse joggle devices do present a few problems. They often have an 'R' in the type number. A reverse package is one where the lead have been bent up instead of down. So it's a mirror image of a conventional device. Identification is usually possible from the code number, but some manufacturers use the same code. In these cases, it's a case of looking at the device with a magnifying glass. The leads of most normal packages come out closer to the circuit board side of the device; conversely a reverse joggle package will have them coming out closer to the 'top' of the device.

Sometimes a series of devices, derived from the same die, have related type (not code) numbers. Often an 'R' will indicate a reverse joggle package, and/or a 'W' indicate a smaller package variant, such as SOT343. Sometimes similarities are also found in the code numbers. For example '67' is the code for a BFP67 (SOT143 package) , and '67R' is the code for the reverse joggle variant BFP67R (SOT143R), while 'W67' is the code for a SOT343 package version.


Leaded equivalent device and information

Where possible, the listing gives the part number of a conventional wire-leaded device with equivalent characteristics. If the leaded device is well-known then no more information is given. If the device is less common, some additional information will sometimes be given. Where no exact leaded equivalent exists, a brief device description is given, which may be sufficient to allow substitution with another device.

When describing device characteristics, some terms are implied from the type of device. For example, a voltage specified for a rectifier diode is usually the maximum PIV (peak inverse voltage) of the diode, but for a zener diode the operating (zener voltage) will be given. Normally, where a voltage, current or power is specified, these will be limiting values. For example, a device specified as npn 20V 0.1A 1W is a NPN transistor with a Vce (max) of 20V, maximum collector current of 100mA and a maximum total power dissipation of 1W. Some of the transistors are types with integrated resistors; in the list, a base resistor means a resistor connected in series with the base. When two resistor values are given, the first is the series base resistor, and the second the resistor between base and emitter.

Digital Transistors (dtr)

These are transistors with built-in resistors, also called 'prebiased transistors'. The Codebook uses 'dtr' as it's shorter... Some have one resistor between base and emitter, others in series with the base lead. Many others have both. To keep things simple, the series resistor is called R1 and the base emitter resistor is called R2. If both are present, then two values are given, R1 first. So 4k7 + 10k means that R1 (the base resistor) is 4k7 and R2 (the resistor between base and emitter) is 10k.

The SMD Codebook is © R P Blackwell.

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