“uSOP” isn’t one standardized package — it’s a nickname at least three manufacturers spell out differently for what turns out to be the same physical outline. Analog Devices/Maxim call theirs “Micro-MAX” (µMAX/uSOP); Diodes Incorporated calls theirs “Ultra Small Outline Package” (USOP); the generic industry term is MSOP (Mini or Micro Small Outline Package). All three are dimensionally compliant with JEDEC MO-187, verified here against five independent manufacturer datasheets.

Key takeaways

• uSOP, USOP, uMAX, Micro-MAX, and MSOP are, dimensionally, the same JEDEC MO-187 outline under different manufacturer trade names — not competing standards.
• The 8-lead variant (MO-187 variation AA) uses 0.65 mm pitch in a ~3.0 × 3.0 mm body; the 10-lead variant (MO-187 variation BA) keeps the same ~3.0 × 3.0 mm body but drops to 0.50 mm pitch to fit two more leads.
• A real distributor-listed part (MAX962EUA+, Maxim’s µMAX-8 dual comparator) measures 3.05 × 3.05 × 0.95 mm — consistent with the JEDEC MO-187 spec, not a separate footprint.
• Maxim and Diodes both use the package-code suffix “UA” for their unrelated 8-pin micro packages — a real naming collision worth knowing before you cross-reference by suffix alone.
• Some MSOP-8/10 variants add an exposed pad with different height and thermal-pad dimensions — don’t assume every uSOP-8 footprint you find is the non-EP version.

What “uSOP” Actually Means

Name used	Manufacturer	Full expansion given	Package code	JEDEC MO-187?
uMAX / uSOP	Analog Devices (Maxim legacy)	“Micro-MAX” internally; combined as “uMAX/uSOP” on the package drawing	UA (8-lead), UB (10-lead)	Yes — matches AA/BA
USOP	Diodes Incorporated	“Ultra Small Outline Package”	UA (UA8)	Yes — within tolerance of AA
MSOP	Generic / Vishay, Microchip, others	“Mini Small Outline Package” (some say “Micro”)	Varies (e.g., Microchip’s MG)	Yes — the standard’s own name

If a datasheet just says “uSOP” with no further context, check which manufacturer wrote it — the expansion changes, the physical footprint generally doesn’t. Two manufacturers’ 8-lead parts under this outline family (Maxim’s uMAX-8 and Diodes’ USOP-8) both land within JEDEC MO-187’s tolerance band, based on the dimension tables below — but always confirm against the specific datasheet before assuming drop-in compatibility, the same caution that applies across this entire package family.

Dimensions

8-lead (JEDEC MO-187, variation AA) — cross-checked against Analog Devices/Maxim’s RM-8 drawing, Vishay’s MSOP-8 package table, and Diodes’ UA8.pdf:

Parameter	Value
Body length (D)	3.00 mm BSC (2.80–3.20 mm range seen across sources)
Body width (E1)	2.90–3.00–3.10 mm
Lead-tip span (E)	4.65–4.90–5.15 mm (4.90 mm BSC per Vishay)
Overall height (A, max)	1.10 mm
Body thickness (A2)	0.75–0.85–0.95 mm
Lead pitch (e)	0.65 mm BSC
Lead width (b)	0.25–0.38 mm
Foot length (L)	0.40–0.55–0.70 mm
Foot angle	0°–6°

10-lead (JEDEC MO-187, variation BA) — cross-checked against Analog Devices/Maxim’s RM-10 drawing and Microchip’s 10-lead MSOP (MG) outline:

Parameter	Value
Body (D × E1)	~3.00 × 3.00 mm (2.80–3.20 mm range) — same body as the 8-lead version
Lead-tip span (E)	4.65–4.90–5.15 mm
Overall height (A, max)	1.10 mm
Lead pitch (e)	0.50 mm BSC
Foot length (L)	0.40–0.55–0.70 mm

Worked observation: the 10-lead variant doesn’t get a bigger body to fit two more leads — it keeps the same ~3.0 × 3.0 mm footprint and tightens pitch from 0.65 mm to 0.50 mm instead. That’s the same design pattern seen across this whole package family (TSSOP going from 0.65 mm to 0.5 mm at higher lead counts) applied at a much smaller scale.

A Real Part, Cross-Checked

Maxim’s MAX962EUA+ (dual comparator, µMAX-8 package) is listed by RS Components at 3.05 × 3.05 × 0.95 mm. That’s inside the JEDEC MO-187 variation AA envelope above — the 0.95 mm height matches the A2 maximum exactly. This is a useful sanity check: a real, currently-distributed part in the “uMAX/uSOP” package genuinely conforms to the generic MSOP-8 numbers, rather than using some separate Maxim-only footprint.

The UA Suffix Trap

Here’s a genuine sourcing gotcha: Maxim’s own package-naming convention uses the suffix “UA” for their 8-lead Micro-MAX/uSOP package. Diodes Incorporated’s package code for their 8-pin Ultra Small Outline Package is also “UA” (as UA8, the literal filename of their package drawing). If you’re scanning part-number suffixes across vendors to identify package type — a common shortcut when triaging a BOM — two completely unrelated companies used the same two letters for their own similarly-sized, but independently-specified, 8-pin package. Confirm package type from the datasheet’s mechanical section, not from a suffix-letter guess.

Exposed-Pad Variants Exist Too

Newer Analog Devices MSOP-8 and MSOP-10 drawings (dated 2024 in the revision history) include an exposed-pad option with its own thermal pad dimensions, distinct from the standard non-EP outline above. If your part’s datasheet mentions a thermal or ground pad on the package underside, don’t reuse a non-EP uSOP/MSOP land pattern — pull the EP-specific drawing for that part.

uSOP/MSOP vs. SOIC-8 vs. TSSOP-8

Attribute	uSOP/MSOP-8 (MO-187 AA)	TSSOP-8, wide variant (MO-153 AA)*	SOIC-8 (MS-012)
Body (L × W)	~3.0 × 3.0 mm	3.0 × 4.4 mm	~4.9 × 3.9 mm
Max height	1.10 mm	1.20 mm	~1.75 mm
Lead pitch	0.65 mm	0.65 mm	1.27 mm
Relative board area	Smallest of the three	~44% more than uSOP-8 (13.2 vs. ~9.0 mm²)	Largest; easiest hand-soldering

*TSSOP-8 figures verified against TI, Renesas, Diodes, and AOS package drawings — see the dedicated TSSOP-8 reference on this site for the full breakdown, including its own separate narrow-body variant.

uSOP/MSOP-8 is the smallest of the three for the same 8 leads, at the cost of being harder to hand-solder than either alternative.

Footprint and Soldering Notes

Pull the land pattern from the specific manufacturer’s datasheet for the exact package code on your part (Maxim’s UA/UB, Diodes’ UA8, or your vendor’s own MSOP designator) rather than approximating one — the small body size leaves little margin for a mismatched pad pitch. At 0.65 mm pitch (8-lead) or 0.50 mm pitch (10-lead), hand-soldering is possible with a fine-tip iron and flux but meaningfully harder than SOIC-8; reflow is the realistic path for production quantities, and the standard J-STD-020 lead-free reflow and MSL considerations covered elsewhere in this package series apply here too — confirm the specific rating on your part’s datasheet.

Selection Path

• You need the smallest possible footprint for an 8-pin analog IC (comparator, reference, small op-amp) and can commit to reflow assembly → uSOP/MSOP-8 is a reasonable fit; confirm the exact manufacturer package code before generating a footprint.
• You need 10 leads in the same tiny footprint → uSOP/MSOP-10 keeps the same ~3×3mm body at a finer 0.50 mm pitch — check your assembly process can handle that pitch reliably.
• You’re prototyping or hand-soldering → SOIC-8’s 1.27 mm pitch and larger body will be far more forgiving than uSOP-8.
• You’re cross-referencing a part across vendors by package-code suffix → don’t trust the suffix letters alone; Maxim and Diodes both use “UA” for unrelated 8-pin packages.

FAQ

What does uSOP stand for?

It depends on the manufacturer. Analog Devices/Maxim call it “Micro-MAX” (branded as uMAX/uSOP); Diodes Incorporated calls their version “Ultra Small Outline Package” (USOP). Both are dimensionally compliant with the generic JEDEC MO-187 standard, commonly called MSOP.

Is uSOP the same as MSOP?

Yes, physically. uSOP/USOP are manufacturer trade names; MSOP is the generic industry term. All the real dimension tables checked here (Analog Devices, Vishay, Microchip, Diodes) fall within JEDEC MO-187’s tolerance range.

What is the pitch of a uSOP package?

0.65 mm for the 8-lead variant (MO-187 AA), 0.50 mm for the 10-lead variant (MO-187 BA) — both in the same ~3.0 × 3.0 mm body.

How big is a uSOP-8 package?

Roughly 3.0 × 3.0 mm body, 1.10 mm max height, per JEDEC MO-187 variation AA. A real distributor-listed part (Maxim MAX962EUA+) measures 3.05 × 3.05 × 0.95 mm.

Can uSOP be hand-soldered?

It’s harder than SOIC-8 due to the small body and 0.65 mm (or 0.50 mm on the 10-lead version) pitch, but doable with a fine-tip iron and flux. Reflow is the realistic path for production.

Are all manufacturers’ uSOP footprints interchangeable?

Generally close, based on the JEDEC MO-187 cross-check here, but not guaranteed — confirm the specific package code and pull that manufacturer’s own land pattern rather than assuming.

What to Do Next

Don’t design a footprint from the label “uSOP” alone. Identify the manufacturer’s specific package code (Maxim/ADI’s UA or UB, Diodes’ UA8, or your vendor’s MSOP designator), confirm whether it’s the standard or exposed-pad variant, and pull that exact drawing’s land pattern rather than reusing one from a different vendor’s “uSOP” part on the assumption the name guarantees the fit.

Suggested internal links

• TSSOP-8 package dimensions, pinout, and footprint → package reference
• TSSOP-64 package dimensions, pinout, and footprint → package reference
• SOIC vs MSOP vs TSSOP package selection → package selection guide
• How to read a JEDEC package outline drawing → package fundamentals

External sources referenced

Diodes Incorporated UA8.pdf (Ultra Small Outline Package) · Analog Devices/Maxim RM-8 and RM-10 (MSOP) package drawings · Analog Devices msop_edrh rh_8_1 and rh_10_1 drawings · Analog Devices 21-0036 (8L uMAX/uSOP) · Vishay 71244.pdf (MSOP-8 dimension table) · Microchip 10-lead MSOP (MG) package outline