SMD package sizes
The same code means different parts in different packages, so the package is the first thing to settle. Most small packages can be told apart with a ruler and a count of the leads.
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Why the package comes first
In our tables, A6 is printed on 261 parts in 28 packages. In SOT-23 alone it is 34 parts.
Names do not settle it on their own. One body can have several names, from JEDEC, from the Japanese standard and from each maker, so the tables give the common ones beside each package.
Three leads
| Outline | Package | Body, mm | With leads, mm | Leads | Other names | Codes in our tables |
|---|---|---|---|---|---|---|
| SOT-23 | 2.9 × 1.3 | 2.9 × 2.4 | 3 | SC-59, TO-236, TO-236AB, SOT-23-3 | 21,305 codes | |
| SOT-323 | 2 × 1.25 | 2.1 × 2 | 3 | SC-70, SC-70-3, SOT-323-3, SOT-323FL | 3,564 codes | |
| SOT-416 | 1.6 × 0.8 | 1.6 × 1.6 | 3 | SC-75, SC-75A, SOT-416FL, EMT3 | 607 codes | |
| SOT-723 | 1.2 × 0.8 | 1.2 × 1.2 | 3 | VMT3, SC-105 | 316 codes | |
| SOT-89 | 4.5 × 2.5 | 4.5 × 4.2 | 3 and a tab | SC-62, TO-243, TO-243AA, SOT-89-3 | 10,774 codes | |
| SOT-223 | 6.5 × 3.5 | 7 × 6.5 | 3 and a tab | SC-73, TO-261, TO-261AA, SOT-223-3 | 2,112 codes |
Drawn to one scale, seen from above, leads included.
SOT-23 and SOT-323 are the pair most often confused. The body of a SOT-23 is 2.9 mm long and that of a SOT-323 2 mm, and the two leads on one side are 1.9 mm apart, centre to centre, on SOT-23 against 1.3 mm on SOT-323.
Four, five and six leads
| Outline | Package | Body, mm | With leads, mm | Leads | Other names | Codes in our tables |
|---|---|---|---|---|---|---|
| SOT-143 | 2.9 × 1.3 | 2.9 × 2.4 | 4 | SOT-143B, SOT-143R, TO-253, SOT-143-4 | 2,379 codes | |
| SOT-23-5 | 2.9 × 1.6 | 2.9 × 2.8 | 5 | SOT-25, SC-74A, TSOP-5, SC-88A | 36,210 codes | |
| SOT-23-6 | 2.9 × 1.6 | 2.9 × 2.8 | 6 | SOT-26, SC-74, TSOP-6, TSOT-23-6 | 32,525 codes | |
| SOT-353 | 2 × 1.25 | 2.1 × 2 | 5 | SC-70-5, SOT-323-5 | 4,130 codes | |
| SOT-363 | 2 × 1.25 | 2.1 × 2 | 6 | SC-88, SC-70-6, SOT-323-6, SOT-363-6L | 2,872 codes | |
| SOT-563 | 1.6 × 1.2 | 1.6 × 1.6 | 6 | SOT-666 | 544 codes |
Count the leads before you look up the code. A SOT-23-5 or a SOT-363 is the size of a three-lead part but holds a different set of parts, often an IC or two transistors in one body.
Two terminals
| Outline | Package | Body, mm | With leads, mm | Other names | Codes in our tables |
|---|---|---|---|---|---|
| SOD-123 | 2.7 × 1.6 | 3.7 × 1.6 | none | 2,007 codes | |
| SOD-123F | 2.7 × 1.6 | 3.7 × 1.6 | SOD-123FL, DO-219AB, SMF | 3,286 codes | |
| SOD-323 | 1.7 × 1.25 | 2.5 × 1.25 | SC-76, SOD-323F, SOD-323FL | 1,840 codes | |
| SOD-523 | 1.2 × 0.8 | 1.6 × 0.8 | SC-79 | 754 codes | |
| SOD-882 | 1 × 0.6 | 1 × 0.6 | DFN1006-2, DFN1006-2L, SOD-882D, DFN1006D-2 | 629 codes | |
| SMA | 4.3 × 2.6 | 5.2 × 2.6 | DO-214AC | 7,679 codes | |
| SMB | 4.4 × 3.6 | 5.4 × 3.6 | DO-214AA | 7,201 codes | |
| SMC | 6.9 × 5.9 | 7.9 × 5.9 | DO-214AB | 7,433 codes | |
| SOD-80 | 3.5 × 1.5 | 3.5 × 1.5 | MiniMELF, LL-34, DO-213AA | 463 codes |
The SOD bodies hold signal diodes, Zeners and small Schottkys. SMA, SMB and SMC are the larger bodies of rectifiers, Schottky rectifiers and TVS diodes. A MELF diode is a small cylinder with metal ends and a band at the cathode.
Measuring without calipers
A steel rule with half-millimetre marks tells most of these apart. Measure the body, not the leads, along its long side.
A chip resistor or capacitor nearby makes a gauge: an 0805 is 2 by 1.25 mm, the same body as a SOT-323, and an 0603 is 1.6 by 0.8 mm.
The four digits of a chip size are its length and width in hundredths of an inch: an 0805 is 0.08 by 0.05 inch.
Try it
Search a code with its package, for example A6 in SOT-23, and compare it with A6 in any package.