GS8721-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 output swing to within ~0.1V of supply rails with RL=600 ohm; typical output current 70mA (55mA min). Closed-loop output impedance ~7.5 ohm at 100kHz (G=1).
2	VSS	power_in	Negative supply / ground reference. Total supply (VDD-VSS) range 2.1V to 5.5V (abs max 7.5V). Input common-mode range extends to VSS-0.1V (rail-to-rail input).
3	IN+	input	Non-inverting input. Rail-to-rail input; common-mode range (VSS-0.1V) to (VDD+0.1V). Very low input bias current (1pA typ) and input offset current (1pA typ). Absolute maximum input voltage: VSS-0.5V to VDD+0.5V.
4	IN-	input	Inverting input. Rail-to-rail input; same electrical limits as IN+. Input offset voltage 0.8mV typ / 3.5mV max at 25C; offset drift 2.4uV/C typ.
5	VDD	power_in	Positive supply. Single-supply operation from +2.1V to +5.5V (abs max 7.5V referenced to VSS). Quiescent current per amplifier 1.1mA typ (1.5mA max at 25C). PSRR 91dB typ.

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.

GS8721-TR
GS8721-CR
GS8721-SR

CAD (KiCad official)

Symbol: GS8721-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
`gs8721-tr.step`	85 KB	You want the bare part, or you mark your own boards.
`gs8721-tr-etched.step`	1.7 MB	You want the part with `GS8721-TR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 420 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 (18 pp, sha256 7d4bae44a19b3397, 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