LM321M5X from HGSEMI, in a SOT-23-5. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	+IN	input	Non-inverting op-amp input. Input common-mode range includes ground and extends to V+ − 1.5V. Typical input bias current 45nA (out of the pin, PNP input stage).
2	V-	power_in	Negative supply / ground pin. Tie to GND for single-supply operation, or to a negative rail for dual-supply operation. Supply voltage (V+ − V-) up to 32V absolute maximum, 3V to 30V operating.
3	-IN	input	Inverting op-amp input. Input common-mode range includes ground and extends to V+ − 1.5V. Typical input bias current 45nA (out of the pin, PNP input stage).
4	OUTPUT	output	Op-amp output. Class-AB stage capable of sourcing ~40mA and sinking up to ~20mA into 2V; slew rate 0.4V/µs; stable driving large capacitive loads. Short-circuit-to-ground current is approximately 40mA (see Absolute Maximum Ratings).
5	V+	power_in	Positive supply pin. Operating range 3V to 30V (32V absolute maximum V+ − V-). Bypass locally with a ceramic capacitor to V-/GND.

Key specifications

Parameter	Value
Manufacturer	HGSEMI
Package	SOT-23-5
Category	Op-amp/Cmp
Pins	5

Ordering variants

Same part, different packaging or reel option.

LM321M5X/TR
LM321M5XM7/TR

CAD (KiCad official)

Symbol: LM321M5X
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`lm321m5x.step`	85 KB	You want the bare part, or you mark your own boards.
`lm321m5x-etched.step`	1.4 MB	You want the part with `LM321M5X` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 363 faces against 102 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: HGSEMI datasheet (12 pp, sha256 8fd8769fe7308caf, retrieved 2026-08-17, tier: lcsc)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF