# LM431ACM3

**Texas Instruments** · Voltage Reference · SOT-23-3

LM431ACM3 from Texas Instruments, in a SOT-23-3. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | Cathode | bidirectional | Shunt regulator output voltage and current terminal; accepts voltage from 2.5 V to 37 V maximum with continuous current range -10 mA to 150 mA. |
| 2 | Reference | input | Reference voltage input pin for adjustable output voltage divider network; typical reference level 2.5 V with maximum input current 10 mA. |
| 3 | Anode | power_in | Ground return terminal normally connected to ground; provides shunt current sink path with continuous current capability -10 mA to 150 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOT-23-3 |
| Category | Power Management (PMIC) |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `LM431ACM3`
- Footprint: `Package_TO_SOT_SMD:SOT-23-3`
- 3D model: SOT-23-3 (KiCad packages3D, STEP)
- 3D model files: `lm431acm3-etched.step` / `lm431acm3-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm431acm3.step` / `lm431acm3.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/cn/lit/gpn/lm431) (37 pp, sha256 `9c0bcff4967eaad2`, retrieved 2026-10-07, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/lm431acm3-datasheet.pdf)