LM321H-TR from Gainsil, 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 analog input of the op-amp. Common-mode input range includes ground and extends to VDD-1.5V. Typical input bias current 20nA.
2	VSS	power_in	Negative supply / ground. Connect to GND in single-supply operation (3V to 36V VDD) or to the negative rail (down to -18V) in dual-supply operation. Bypass with a 0.1µF ceramic capacitor to ground in split-supply designs.
3	IN-	input	Inverting analog input of the op-amp. Same common-mode range and bias current characteristics as IN+.
4	OUT	output	Op-amp output. Swings from 0V to VCC-1.5V; sources/sinks 40mA typical (60mA max) into a 10Ω load to VS/2. Output high VOH ≥12V and low VOL ≤5mV typical at RL=10kΩ with VS=15V.
5	VDD	power_in	Positive supply. Single-supply range 3V to 36V, or up to +18V in dual-supply operation. Bypass with a 0.1µF ceramic capacitor to VSS placed close to the pin.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

LM321H-TR
LM321H-TRLM358H-SR
LM321H-TRLM358H-MR
LM324H-SR
LM324H-TR

CAD (KiCad official)

Symbol: LM321H-TR
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
`lm321h-tr.step`	85 KB	You want the bare part, or you mark your own boards.
`lm321h-tr-etched.step`	1.4 MB	You want the part with `LM321H-TR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 360 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: Gainsil datasheet (14 pp, sha256 1b038a6ed7d0cd56, 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