Component Package Names: A Complete Guide — size comparison of 0603, SOD-123, SMA, DO-41, SOT-23, DPAK, TO-220
Picture: A customer has three black SMD parts that differ only in size on the palm of his hand and asks, “They all look the same — what’s the difference?” The female staff member wearing glasses holds up a ruler and answers, “Measure the size and you’ll see the name.”
Even with the same part number, a part in a different package (shape and size) won't fit the board. Yet package names vary by company and by standard, so the same shape may go by two or three names. We've drawn the packages you meet most often at actual size (with a ruler) and enlarged, together with their names. On a PC (24-inch FHD, 100% scaling) and on iPhone they appear at actual size as is; on other screens, use 📏 Calibrate ruler next to the first figure to match a real ruler.
Dimensions are approximate. Diodes are based on the package dimension tables (nominal values) in the WTE datasheets in the eGuro Semiconductor Library, chips on the Yageo chip resistor datasheet, and transistors, bridges and ICs on general JEDEC dimensions. They differ by about 0.1~0.3mm between manufacturers, so use the relevant datasheet for design.
1. Why there are two names
2. Chip resistors & MLCCs — 4 digits = size
3. SMD diodes — SOD · SMA · SMB · SMC
4. Leaded diodes — DO-35 · DO-41 · DO-15 · DO-201AD
5. Transistors & FETs — SOT-23 · DPAK · TO-220
6. Bridge diodes — DF · MB · KBP · GBU · KBPC
7. ICs — DIP · SOP · TSSOP · QFN
8. What to check when ordering
1. Why are there two names for each?
Picture: A customer holds a reel labeled DO-214AC and a bag labeled SMA and asks, “The names are different — are they different parts?” The female staff member points to both labels and answers, “Same shape, just two names.”
That's because the same package has both a standard name (numeric, like JEDEC's DO-214AC or TO-252) and a common name (given by the industry, like SMA or DPAK). Datasheets often list both, as in "SMA (DO-214AC)", while labels and quotes may show only one. The two names in the table below refer to the same package.
| Common name | Other name (standard name) |
|---|---|
| SMA | DO-214AC |
| SMB | DO-214AA |
| SMC | DO-214AB |
| MiniMELF | SOD-80 · DO-213AA |
| MELF | DO-213AB |
| DO-41 | DO-204AL |
| DO-15 | DO-204AC |
| DO-201AD | DO-27 |
| DPAK | TO-252 |
| D²PAK | TO-263 |
| SOT-23 | TO-236 |
| SOT-23-6 | SC-74 |
| ITO-220 | TO-220F · Full-pak |
| SOP | SOIC |
2. Chip resistors · MLCCs — 4 digits = size
Actual size
↓ Actual size, left edge aligned to 0 on the ruler (1 ruler division = 1mm)
Enlarged (same scale)
| inch code | Other names · Use | Size |
|---|---|---|
| 0201 | mm code 0603 | 0.6 × 0.3mm |
| 0402 | mm code 1005 | 1 × 0.5mm |
| 0603 | mm code 1608 | 1.6 × 0.8mm |
| 0805 | mm code 2012 | 2 × 1.25mm |
| 1206 | mm code 3216 | 3.2 × 1.6mm |
| 1210 | mm code 3225 | 3.2 × 2.5mm |
| 2512 | mm code 6432 | 6.4 × 3.2mm |
Don't order by the number alone
Chip resistors, MLCCs and chip inductors are named by their length and width as 4 digits. There is an American inch code (0603 = 0.06 × 0.03 inch) and an mm code widely used by Japanese and Korean manufacturers (1608 = 1.6 × 0.8mm), so "0603" can mean 1.6mm or 0.6mm depending on the company. Murata and Samsung part numbers contain the mm code (for details see How to Read MLCC Part Numbers). When quoting just the number, it's safer to add the unit, as in "inch 0603".
| inch | mm | Size (mm) | Common use |
|---|---|---|---|
| 0201 | 0603 | 0.6 × 0.3 | Phones · modules (hand soldering nearly impossible) |
| 0402 | 1005 | 1.0 × 0.5 | General small devices |
| 0603 | 1608 | 1.6 × 0.8 | Most common size |
| 0805 | 2012 | 2.0 × 1.25 | General use · easy hand soldering |
| 1206 | 3216 | 3.2 × 1.6 | Power · high voltage |
| 1210 | 3225 | 3.2 × 2.5 | High-capacitance MLCC |
| 2512 | 6432 | 6.4 × 3.2 | Current-sense resistors (1W class) |
The numeric codes printed on chip resistors (103, 4R7, 01C, etc.) are explained in How to Read SMD Resistor Codes.
3. SMD diodes — SOD · SMA · SMB · SMC
Actual size
↓ Actual size, left edge aligned to 0 on the ruler (1 ruler division = 1mm)
Enlarged (same scale)
| Package | Other names · Use | Size |
|---|---|---|
| SOD-523 | - | 1.2 × 0.8mm |
| SOD-323 | - | 1.7 × 1.3mm |
| SOD-123 | - | 2.6 × 1.6mm |
| SOD-123FL | Flat-terminal type | 2.8 × 1.8mm |
| SMA | DO-214AC | 4.3 × 2.6mm |
| SMB | DO-214AA | 4.4 × 3.6mm |
| SMC | DO-214AB | 6.8 × 5.9mm |
(TVS 400W · 600W · 1500W)
For SOD-523 · SOD-323 · SOD-123, the smaller the number, the more it is for small-signal, low-current use (1N4148W, BZT52C5V1, etc.). SOD-123FL is similar in size to SOD-123 but has flat terminals under the body, so their footprints differ. SMA · SMB · SMC are for power uses such as rectifiers, Schottky and TVS; even within the same family, a larger package means higher current and power: S1M (SMA, 1A) · S2M (SMB, 2A) · S3M (SMC, 3A), and for TVS, SMAJ 400W · SMBJ 600W · SMCJ 1500W.
MiniMELF (SOD-80) is a cylindrical SMD shaped like a glass tube, used for small-signal diodes and Zeners such as LL4148.
How to read current and voltage from part number characters is covered in How to Read Diode Part Numbers.
4. Leaded diodes — DO-35 · DO-41 · DO-15 · DO-201AD
Actual size
↓ Actual size, left edge aligned to 0 on the ruler (1 ruler division = 1mm)
Enlarged (same scale)
| Package | Other names · Use | Size |
|---|---|---|
| DO-35 | Glass · 1N4148 | Body 3.8mm Diameter 1.8mm |
| DO-41 | DO-204AL · 1N4007 | Body 4.6mm Diameter 2.4mm |
| DO-15 | DO-204AC · P6KE | Body 6.6mm Diameter 3.1mm |
| DO-201AD | DO-27 · 1N5408 | Body 8.4mm Diameter 5.1mm |
Axial diodes with leads on both ends are named by DO- number. They're easy to remember by representative parts: DO-35 glass 1N4148 · DO-41 1N4007 (1A) · DO-15 2A class and P6KE TVS · DO-201AD (DO-27) 3~5A class such as 1N5408 (3A). The side with the band on the body is the cathode (−).
5. Transistors · FETs — SOT-23 · DPAK · TO-220
Actual size
↓ Actual size, left edge aligned to 0 on the ruler (1 ruler division = 1mm)
Enlarged (same scale)
| Package | Other names · Use | Size |
|---|---|---|
| SOT-23 | TO-236 | 2.9 × 1.3mm |
| SOT-23-6 | SC-74 · 5-pin is SOT-23-5 | 2.9 × 1.6mm |
| SOT-89 | - | 4.5 × 2.5mm |
| SOT-223 | - | 6.5 × 3.5mm |
| DPAK | TO-252 | 6.6 × 6.1mm |
| D²PAK | TO-263 | 10.1 × 9.2mm |
| TO-220 | Screw hole in the tab | 10.2 × 15.3mm (including tab) |
| ITO-220 | TO-220F · Full-pak | 10.2 × 15.9mm |
| TO-247 | Similar to TO-3P | 15.9 × 20.9mm |
Even with the same shape, pin order varies by part
| Package | Other names | Shape | Typical use |
|---|---|---|---|
| SOT-23 | TO-236 | 3-lead SMD (2.9 × 1.3mm) | Small-signal transistors · FETs · diodes |
| SOT-23-5 · SOT-23-6 | SC-74A · SC-74 | SOT-23 with 5 or 6 leads | LDOs · small ICs |
| SOT-89 · SOT-223 | — | SMD with a heat-sink tab | 1A-class regulators · transistors |
| DPAK | TO-252 | Small SMD, like a TO-220 laid flat | Power FETs · regulators |
| D²PAK | TO-263 | SMD larger than DPAK | High-current FETs · Schottky |
| TO-220 | — | Heat-sink tab with screw hole + 3 leads | Regulators · FETs · MBR Schottky |
| ITO-220 | TO-220F · Full-pak | TO-220 with the heat-sink tab also covered in resin | Mounts directly on a heat sink without insulation |
| TO-247 · TO-3P | — | High-power type, larger than TO-220 | IGBTs · high-current FETs |
Even within SOT-23, the lead arrangement (pin order) differs from part to part. Always check the pinout in the datasheet before swapping parts just because they look the same. The package letters within FET part numbers (Infineon P = TO-247, etc.) are tabulated in How to Read FET Part Numbers.
6. Bridge diodes — DF · MB · KBP · GBU · KBPC
Actual size
↓ Actual size, left edge aligned to 0 on the ruler (1 ruler division = 1mm)
Enlarged (same scale)
| Package | Other names · Use | Size |
|---|---|---|
| MB(S) | 0.5~1A · SMD | 4.8 × 4.0mm |
| DF(S) | 1A · S = SMD | 8.3 × 6.5mm |
| KBP | 1.5~2A | 14.5 × 11mm |
| GBU | 4~8A | 22 × 18mm |
| KBU | 4~8A | 23.5 × 19mm |
| KBPC | 15–35A · screw mount | 28.6 × 28.6mm |
For bridge diodes, the leading letters of the part number are the package. From smallest: MB(S) small SMD (0.5~1A) · DF(S) 4-pin DIP shape (1A, S is SMD) · KBP flat 4-pin (1.5~2A) · GBU · KBU single-row 4-pin with heat dissipation (4~8A) · KBPC square metal, screw-mounted (15~35A). Even at the same voltage, as with MB10S, KBP210 and KBPC3510, different packages have different sizes and lead arrangements and cannot be swapped.
7. IC — DIP · SOP · TSSOP · QFN
Actual size
↓ Actual size, left edge aligned to 0 on the ruler (1 ruler division = 1mm)
Enlarged (same scale)
| Package | Other names · Use | Size |
|---|---|---|
| DIP-8 | Lead pitch 2.54mm | 9.6 × 6.4mm |
| SOP-8 | SOIC-8 · pitch 1.27mm | 4.9 × 3.9mm |
| TSSOP-8 | Pitch 0.65mm | 3.0 × 4.4mm |
| QFN-16 | No leads · bottom pads | 3 × 3mm |
| LQFP-48 | Leads on four sides · pitch 0.5mm | 7 × 7mm |
| BGA (example) | Solder balls on bottom · pitch 0.8mm | 10 × 10mm |
QFN · BGA are nearly impossible to replace without equipment
| Package | Lead pitch | Features |
|---|---|---|
| DIP (PDIP) | 2.54mm | Two rows of through-hole leads. Works with breadboards and sockets |
| SOP · SOIC | 1.27mm | SMD at half the size of DIP. The most common IC package |
| SSOP · TSSOP | Around 0.65mm | Narrower pitch and thinner body than SOP |
| QFP · LQFP | 0.5~0.8mm | Leads on all four sides. Common for MCUs |
| QFN · DFN | Around 0.5mm | No leads, pads on the bottom. Small with good heat dissipation, but hard to hand-solder |
| BGA | Ball array | Solder balls on the bottom. Cannot be soldered or replaced without equipment |
The same IC chip often comes in several packages, usually distinguished by the suffix of the part number (N = DIP, D = SOIC, PW = TSSOP, etc. — varies by company). Before ordering, check the package in the "Ordering Information" table of the datasheet.
8. What to check when ordering
- Search for both package names — SMA and DO-214AC, DPAK and TO-252 are the same.
- Check whether a chip size is in inches or mm — a single 0603 can mean 1.6mm or 0.6mm.
- Pinouts can differ even when the shape is the same — especially for SOT-23 and TO-220, check the datasheet pinout.
- Variants with similar names, such as SOD-123 and SOD-123FL or TO-220 and ITO-220, differ in footprint and heat dissipation.
- The surest method is to measure the part you're using with a ruler and compare it with the tables above.
Sources: Won-Top (WTE) datasheet package dimension tables · Yageo RC chip resistor datasheet · JEDEC package names and typical dimensions. Dimensions in the figures are approximate and vary slightly by manufacturer.