GS331-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	INPUT-	input	Inverting comparator input. Input common-mode range includes ground; upper end is VCC-1.5V. Should not be driven more than 0.3V below ground. Typical input bias current 25nA.
2	GND	power_in	Ground / negative supply return. For single-supply operation tie to 0V; for split-supply operation connect to the negative rail (±1.0V to ±18V).
3	INPUT+	input	Non-inverting comparator input. Input common-mode range includes ground; upper end is VCC-1.5V. Should not be driven more than 0.3V below ground. Typical input bias current 25nA.
4	OUTPUT	output	Open-collector comparator output. Requires an external pull-up resistor to VCC (or another rail up to 40V). Typical sink current 16mA; saturation voltage 200mV at 4mA sink; leakage 0.1nA typ.
5	VCC	power_in	Positive supply input. Single supply 2.0V to 36V or split supply +1.0V to +18V. Absolute maximum 40V (single) or ±20V (split). Typical supply current 0.4mA at 5V.

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.

GS331-TR

CAD (KiCad official)

Symbol: GS331-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
`gs331-tr.step`	85 KB	You want the bare part, or you mark your own boards.
`gs331-tr-etched.step`	1.7 MB	You want the part with `GS331-TR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 412 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 (10 pp, sha256 535ed4507a80be0f, 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