LM321 from Slkor SLKORMICRO Elec, 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 bias current typ. ±45 nA (max ±250 nA); common-mode input voltage range includes ground up to V+ − 1.5 V.
2	V-	power_in	Negative supply / ground pin. Tie to GND for single-supply operation, or to the negative rail for split-supply operation (±12 V max, 24 V total across V+ to V-).
3	-IN	input	Inverting op-amp input. Input offset voltage typ. ±2 mV (max ±5 mV); differential input voltage rating 24 V.
4	OUT	output	Op-amp output. Source current typ. 40 mA, sink current typ. 15 mA; short-circuit current to ground typ. 40 mA. Stable driving large capacitive loads.
5	V+	power_in	Positive supply pin. Absolute maximum supply voltage 24 V (single) or ±12 V (split). Supply current typ. 0.5 mA at V+ = 5 V, 0.7 mA at V+ = 24 V.

Key specifications

Parameter	Value
Manufacturer	Slkor SLKORMICRO Elec
Package	SOT-23-5
Category	Op-amp/Cmp
Pins	5

CAD (KiCad official)

Symbol: LM321
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
`lm321.step`	85 KB	You want the bare part, or you mark your own boards.
`lm321-etched.step`	1.0 MB	You want the part with `LM321` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 265 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: Slkor SLKORMICRO Elec datasheet (5 pp, sha256 6163ed0d8bef93ca, 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