GS8591-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	OUT	output	Amplifier output. Rail-to-rail swing to within ~5mV of VDD/VSS on light loads (>100kΩ) and ~60mV on 10kΩ loads. Short-circuit current is typically 43mA.
2	VSS	power_in	Negative supply / ground. Together with VDD sets the supply range of 1.8V to 5.5V (single-supply) or ±0.9V to ±2.75V (dual-supply). Decouple with a 0.1µF ceramic to ground for dual-supply operation.
3	IN+	input	Non-inverting input. Input common-mode range extends 100mV beyond the supply rails (VSS-0.1V to VDD+0.1V). Typical input bias current is 20pA.
4	IN-	input	Inverting input. Input common-mode range extends 100mV beyond the supply rails (VSS-0.1V to VDD+0.1V). Typical input bias current is 20pA.
5	VDD	power_in	Positive supply. Operating range 1.8V to 5.5V; absolute maximum VDD-VSS = 7.5V. Bypass with a 0.1µF ceramic capacitor 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.

GS8591-TR
GS8591-SR
GS8592-MR
GS8592-SR
GS8594-TR
GS8594-SR

CAD (KiCad official)

Symbol: GS8591-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
`gs8591-tr.step`	85 KB	You want the bare part, or you mark your own boards.
`gs8591-tr-etched.step`	1.9 MB	You want the part with `GS8591-TR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 459 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 1b646d2c2feb461f, 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