The common TSOP-32 package is a Type I outline: 32 gull-wing leads on 0.50 mm pitch, 16 per short edge, an 8 mm body width and a 20 mm lead span. It is also the most overloaded designation in the TSOP family. Five separate JEDEC registrations cover 32 leads, across both lead types and four body widths. Below are the geometries, the measurement that separates them, and the footprint work you can skip.
Key takeaways
- The mainstream part is 8 mm body width, 18.4 mm body length, 20.0 mm lead span, 0.50 mm pitch, 1.20 mm maximum height.
- A second Type I geometry exists at 8 × 13.4 mm, used on some SRAM.
- Thirty-two leads appear in five JEDEC registrations, more than any other count in the TSOP family.
- The 32-lead and 48-lead Type I share pad size, row spacing and lead span. Only the number of pads and the array length differ.
- “TSOP28/32” is not a typo. It means a 32-lead outline with 28 leads populated.
- Searching a distributor for “TSOP32” returns Vishay infrared receivers before it returns any package.
[IMAGE 1: TSOP-32 Type I outline with 16 leads per short edge, 20 mm lead span and 0.5 mm pitch dimensioned | alt: “TSOP-32 package dimensions showing 0.5 mm pitch, 8 mm body width and 20 mm lead span”]
What a TSOP-32 package is
A TSOP-32 package is a 32-lead thin small outline package with gull-wing leads on 0.50 mm pitch and a maximum seated height of 1.20 mm. In its common form it is Type I, with 16 leads on each of the two shorter edges, an 8 mm body width and a 20 mm lead span. Parallel NOR flash, EPROM and SRAM all use it.
STMicroelectronics writes the size into its ordering scheme directly: on the M27C801, package code N is TSOP32, 8 × 20 mm. onsemi’s CAT28F010H and ST’s M29W040B carry the same 8 × 20 mm description in distributor records.
Five JEDEC registrations cover 32 leads
Count the appearances of 32 in the JEDEC JEP95 device-type index, updated March 2026, and the problem with the name becomes obvious.
| Registration | Family | Registered lead counts |
| MO-142 | TSOP Type I | 24, 32, 40, 48, 56 |
| MO-133 (replaced by MS-024) | TSOP II, 10.16 mm body | 28, 32, 44 |
| MO-135 | TSOP II, 12.70 mm body | 32, 34, 50, 54 |
| MO-201 | TSOP II, 2-high and 4-high stacked | 32 |
| MO-249 | Thin SO, 8.89 mm body | 28, 32, 36, 40, 44, 52, 56, 64, 68 |
No other lead count in the family reaches five. Twenty-eight appears three times, and 44, 48 and 54 appear twice each. A part described only as “TSOP-32” could be any of these, and the four body widths involved are 8 mm, 8.89 mm, 10.16 mm and 12.70 mm.
The measurement that separates them in seconds is which edge the leads come from. If they emerge from the short edges, it is Type I and the body is about 8 mm wide. If they emerge from the long edges, it is Type II and you then measure the width to pick between 10.16 mm and 12.70 mm.
TSOP-32 dimensions
Two Type I geometries are in circulation, and they differ only in body length.
| Parameter | 8 × 20 mm variant | 8 × 13.4 mm variant |
| Body width | 8.0 mm | 8.0 mm |
| Body length | 18.4 mm | 13.4 mm |
| Lead span | 20.0 mm | take from drawing |
| Pitch | 0.50 mm | 0.50 mm |
| Leads per edge | 16 | 16 |
| Max height | 1.20 mm | 1.20 mm |
| Seen on | ST M27C801 and M29W040B, onsemi CAT28F010H | Renesas µPD431000A SRAM |
The 8 × 20 mm figure follows the family convention where the second number is the lead span rather than the body length. Socket makers confirm the body: Dataman’s programmer adapters for this part are catalogued as DIL32/TSOP32 ZIF 18.4 mm, with a rated socket life of 10,000 actuations.
The lead row behaves exactly as the Type I family rule predicts:
16 leads per edge, 15 × 0.50 mm = 7.5 mm row in an 8.0 mm body
That leaves 0.25 mm of body at each end of the row, the same margin the 40, 48 and 56-lead sizes use. Microchip’s drawing for its 32-lead TSOP adds the tolerance detail worth knowing: maximum allowable mold flash is 0.15 mm at the package ends and 0.25 mm between leads. Add the relevant figure to the nominal body before you draw a courtyard.
I did not open a full min-and-max table for the 8 × 13.4 mm variant, so treat its lead span as unknown until you have the drawing for the specific part.
The footprint you already have
Here is the piece of work you can skip. The 32-lead and 48-lead Type I outlines share the same 0.50 mm pitch, the same 20.0 mm lead span, and the same lead width and foot length ranges. Run the IPC-7351B nominal calculation on either and you get the same pad.
| Land pattern parameter | 32-lead | 48-lead |
| Pad size | 0.35 mm × 1.65 mm | 0.35 mm × 1.65 mm |
| Row centreline spacing | 19.25 mm | 19.25 mm |
| Outer pad extent (Z) | 20.91 mm | 20.91 mm |
| Pad-to-pad clearance | 0.15 mm | 0.15 mm |
| Pads per row | 16 | 24 |
| Pad array length | 7.85 mm | 11.85 mm |
| Total copper | 18.5 mm² | 27.7 mm² |
Only the pad count and the array length change. If your library already holds a compliant 48-lead Type I footprint, deriving the 32-lead version is a matter of deleting eight pads per row and recentring, not of starting over.
The 0.15 mm clearance carries the same consequence at 32 leads as at 48: no track passes between adjacent pads at standard design rules, so every net escapes outward or drops to an inner layer.
Pinout and pin-1 identification
Numbering runs down one lead row and back up the other, with pin 1 at the marked index corner and pin 16 facing pin 17 across the far end.
Function assignment follows the device, not the package, but 32-lead parallel memory is heavily conventional. The address bus, data bus and the CE#, OE# and WE# control set occupy predictable positions across vendors, which is why 32-lead flash from different suppliers has historically dropped into the same board.
Pin-1 marking deserves its own rule, because more than one marker can appear on the same part. Intel’s Small Outline Package Guide sets the precedence explicitly for the TSOP family:
- If both a dimple and a triangle are present, the triangle denotes pin 1.
- If only a dimple is present, the dimple denotes pin 1.
- If two dimples are present, the larger dimple denotes pin 1.
That third case is the one that catches people. Two dimples on a thin package are easy to read as a single ambiguous mark under a bench light.
[IMAGE 2: TSOP-32 top view with dimple and triangle pin-1 markers annotated | alt: “TSOP-32 package pinout with pin 1 dimple and triangle marking precedence”]
What “TSOP28/32” means
Vendor catalogs list packages as TSOP28/32, TSOP20/24, TSOP24/28, TSOP40/44 and TSOP44/50. TopLine’s package catalog carries the full set. The notation is not a range and not an error: it means a body built on the larger lead frame with the smaller number of leads populated, so a TSOP28/32 device sits on a 32-lead outline with four positions depopulated.
Two consequences follow. A 28-lead part of this kind will land correctly on a 32-lead footprint, with four pads left unsoldered. And a 32-lead footprint in your library may be the right choice for a part whose datasheet says 28 leads, provided the drawing confirms the outline. Check the drawing rather than the lead count.
The same catalogs list sTSOP-32 as a separate item, which is a shrunk variant and not interchangeable.
Sourcing
The name is the first obstacle. Vishay’s TSOP322, TSOP324, TSOP344 and TSOP348 series are infrared receiver modules, still current at revision 2.1 dated 23 May 2025 and shipped 2,160 pieces per tube. A distributor search for “TSOP32” returns them ahead of any package. Filter by category, or search the package field, which DigiKey renders as “32-TSOP”.
What still ships is mostly parallel flash. Microchip’s SST39SF010A, SST39SF020A and SST39SF040 datasheet, document DS20005022F, is maintained across 2002 to 2025 and offers the same die in 32-lead TSOP, 32-lead PLCC and a 600 mil 32-pin PDIP. Having three packages for one die is unusual today and makes this family useful for designs that need a socketed prototype and a surface-mount production build.
Watch the package codes on these parts. Microchip has issued change notices replacing the WHE package type with TU on the SST39LF and SST39VF families, and updating the 32-lead TSOP package marking effective 12 June 2025. Neither changes the outline, but both change the ordering string and the marking your incoming inspection is checking against.
Five mistakes on TSOP-32 designs
- Treating “TSOP-32” as one package. Five registrations, four body widths. Identify the type before anything else.
- Assuming 8 × 20 means the body. The second number is the lead span; the body is 18.4 mm long.
- Misreading two dimples. The larger one is pin 1. A triangle overrides both.
- Rejecting a 28-lead part on a 32-lead footprint. TSOP28/32 parts are built for exactly that.
- Searching a distributor for TSOP32. You will get infrared receivers. Search the package field.
TSOP-32 FAQ
What are TSOP-32 package dimensions?
For the common Type I variant: 8.0 mm body width, 18.4 mm body length, 20.0 mm lead span, 0.50 mm lead pitch, 1.20 mm maximum seated height, with 16 leads on each short edge. A second Type I geometry exists at 8 × 13.4 mm. Type II 32-lead parts use 10.16 mm or 12.70 mm bodies.
What is the pitch of a TSOP-32?
0.50 mm on the Type I variants used for flash, EPROM and SRAM. Sixteen leads per edge occupy 7.5 mm of the 8 mm body width, leaving 0.25 mm at each end. Type II 32-lead parts registered under MO-133 and MO-135 can use coarser pitches, so confirm against the drawing.
Is TSOP-32 the same as TSSOP-32?
No. They are separate JEDEC families with different bodies, even though both can use 0.50 mm pitch. TSOP-32 in its common form is 8 mm wide with leads on the short edges and a 20 mm lead span. Do not substitute one footprint for the other without comparing drawings.
What does TSOP28/32 mean?
A 32-lead package outline with 28 leads populated and four positions depopulated. The body, pitch and lead span match the 32-lead part. Such a device mounts on a 32-lead footprint with four pads left unsoldered. Vendor package catalogs use the same notation for TSOP20/24, TSOP24/28, TSOP40/44 and TSOP44/50.
Why does searching TSOP32 return infrared receivers?
Because Vishay’s TSOP322, TSOP324, TSOP344 and TSOP348 series are IR receiver modules whose part numbers begin with the same string. They are current products, not legacy stock. Filter by product category first, then by package, or search the distributor’s package field for “32-TSOP”.
Choosing TSOP-32
Specify TSOP-32 when the memory you need ships in it, when you want a footprint that is inspectable without X-ray, and when you can give the part room to escape 16 nets at each end. For 1 Mbit to 4 Mbit parallel flash in industrial equipment, it remains a sound and well-supplied choice, and the availability of the same die in PLCC-32 and PDIP-32 makes prototyping easy.
Move to a higher lead count in the same family if the density demands it; the footprint work carries over almost unchanged. Move to a serial interface entirely if the parallel bus is the only reason you are here.
Before committing: confirm the lead type from the drawing, take the lead span rather than the body length, and check whether your library’s 48-lead Type I footprint can be trimmed instead of redrawn. The first prevents a scrapped board, the second prevents a respin, and the third saves an afternoon.
[IMAGE 3: 32-lead and 48-lead Type I footprints overlaid showing shared pad geometry | alt: “TSOP-32 package footprint compared with the 48-lead Type I showing identical pad size and row spacing”]
Internal links to add
- [INTERNAL LINK: TSOP package → the full TSOP family, registrations and land patterns]
- [INTERNAL LINK: TSOP Type I → short-side lead layout and escape routing]
- [INTERNAL LINK: TSOP Type II → long-side lead layout and the 400-mil family]
- [INTERNAL LINK: IPC-7351 land pattern density levels → choosing Most, Nominal or Least]
- [INTERNAL LINK: PLCC-32 package → socketed alternatives for 32-lead memory]
