# LR78L09A

**LRC** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · SOT-89

LR78L09A from LRC, in a SOT-89. 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 | Vout | power_out | Regulated +9 V output. Typical 9.0 V (min 8.64 V, max 9.36 V at Tj=25°C). Supplies up to 100 mA. A 0.1 µF bypass capacitor to GND close to the pin is recommended for stability and transient response. |
| 2 | GND | power_in | Ground / common return. On SOT-89 this pin is electrically tied to the large center tab used as the thermal pad. |
| 3 | Vin | power_in | Unregulated input voltage. Absolute max 30 V for the 9 V option; recommended range 11.5 V to 24 V. Dropout ~1.7 V typical. A 0.33 µF bypass capacitor to GND close to the pin is recommended. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | LRC |
| Package | SOT-89 |
| Category | PMIC |
| Pins | 3 |

## Ordering variants

Same part, different packaging or reel option.

- `LR78L09A`
- `LR78L09B`

## CAD (KiCad official)

- Symbol: `LR78L09A`
- Footprint: `Package_TO_SOT_SMD:SOT-89-3`
- 3D model: SOT-89 (KiCad packages3D, STEP)
- 3D model files: `lr78l09a-etched.step` / `lr78l09a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lr78l09a.step` / `lr78l09a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [LRC datasheet](docs/lr78l09a-datasheet.pdf) (8 pp, sha256 `e540f0f8c27d9693`, 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](docs/lr78l09a-datasheet.pdf)