# LP3990MFX-1.2

**Texas Instruments** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · SOT-23-5

LP3990MFX-1.2 from Texas Instruments, in a SOT-23-5. 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 | IN | power_in | Voltage supply input; a 1-µF capacitor should be connected at this input, and the recommended input range is 2 V to 6 V. |
| 2 | GND | power_in | Common ground; all voltages in the datasheet are referenced to this pin. |
| 3 | EN | input | Enable input: the regulator is enabled when EN is at or above 0.95 V and disabled when at or below 0.4 V, with a 1-MΩ (typical) internal pull-down to GND; the recommended EN voltage range is 0.0 V to VIN. |
| 4 | N/C | unconnected | No internal connection. |
| 5 | OUT | power_out | Voltage output; a 1-µF low-ESR capacitor should be connected to this pin, and it connects to the load circuit. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOT-23-5 |
| Category | Power Management (PMIC) |
| Pins | 5 |

## CAD (KiCad official)

- Symbol: `LP3990MFX-1.2`
- Footprint: `Package_TO_SOT_SMD:SOT-23-5`
- 3D model: SOT-23-5 (KiCad packages3D, STEP)
- 3D model files: `lp3990mfx-1-2-etched.step` / `lp3990mfx-1-2-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lp3990mfx-1-2.step` / `lp3990mfx-1-2.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/lp3990) (30 pp, sha256 `29d422eb70ba7b94`, retrieved 2026-10-09, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (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/lp3990mfx-1-2-datasheet.pdf)