# INA138NA

**Texas Instruments** · Current-Sensing Amplifiers · SOT-23-5

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 files: `ina138na-etched.step` / `ina138na-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ina138na.step` / `ina138na.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`ina138na.step`](ina138na.step) | 85 KB | You want the bare part, or you mark your own boards. |
| [`ina138na-etched.step`](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](https://www.ti.com/lit/ds/symlink/ina138.pdf) (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](docs/ina138na-datasheet.pdf)