GS8591-SR from Gainsil, in a SOP-8. 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	NC	unconnected	No internal connection. Leave floating or tie to any convenient potential; not electrically bonded to the die.
2	IN-	input	Inverting analog input of the op amp. Rail-to-rail input range extends 100mV beyond the supply rails (VSS-0.1V to VDD+0.1V). Typical input bias current 20pA.
3	IN+	input	Non-inverting analog input of the op amp. Rail-to-rail input range extends 100mV beyond the supply rails (VSS-0.1V to VDD+0.1V).
4	VSS	power_in	Negative supply / ground pin. For single-supply operation tie to GND; for dual-supply operation connect to the negative rail (down to -2.75V). Bypass with 0.1µF ceramic close to the device.
5	NC	unconnected	No internal connection. Leave floating or tie to any convenient potential.
6	OUT	output	Amplifier output. Rail-to-rail output swing: typically to within 5mV of the supply rail with a 10kΩ load and less than 5mV with light loads. Short-circuit current 43mA typical; continuous output current 30mA typical.
7	VDD	power_in	Positive supply pin. Operates from 1.8V to 5.5V single-supply (absolute max VDD-VSS = 7.5V). Bypass with a 0.1µF ceramic capacitor located close to this pin.
8	NC	unconnected	No internal connection. Leave floating or tie to any convenient potential.

Key specifications

Parameter	Value
Manufacturer	Gainsil
Package	SOP-8
Category	Op-amp/Cmp
Pins	8

Ordering variants

Same part, different packaging or reel option.

GS8591-SR
GS8591-TR

CAD (KiCad official)

Symbol: GS8591-SR
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`gs8591-sr.step`	122 KB	You want the bare part, or you mark your own boards.
`gs8591-sr-etched.step`	2.3 MB	You want the part with `GS8591-SR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 552 faces against 147 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