INA138NA from Texas Instruments, 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	Output current pin. Sources a current proportional to the differential sense voltage (VIN+ − VIN−) with transconductance of 200 µA/V; an external load resistor RL converts this current to an output voltage VO = IS · RS · RL / 5 kΩ.
2	GND	power_in	Ground reference for the device.
3	VIN+	input	Positive differential input; connects to the high side of the external shunt resistor RS. Common-mode range 2.7 V to 36 V (INA138) is independent of the supply voltage V+.
4	VIN-	input	Negative differential input; connects to the load side of the external shunt resistor RS. Full-scale sense voltage (VIN+ − VIN−) up to 500 mV.
5	V+	power_in	Power supply input. Operating range 2.7 V to 36 V for the INA138; independent of the input common-mode voltage. Quiescent current 25 µA typical.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

INA138NA
INA138NA/250
INA138NA/3K

CAD (KiCad official)

Symbol: INA138NA
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
`ina138na.step`	85 KB	You want the bare part, or you mark your own boards.
`ina138na-etched.step`	1.4 MB	You want the part with `INA138NA` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 364 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: Texas Instruments datasheet (28 pp, sha256 381c48493d9daa2e, retrieved 2026-08-17, tier: manufacturer)
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