# 78L12

**UMW** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · SOT-89-3

78L12 from UMW, in a SOT-89-3. Pinout and pin descriptions extracted from the datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | Output | power_out | Regulated +12V output. Delivers up to 100 mA (typ) with ~1.7 V dropout. Requires a ceramic bypass capacitor (CO=0.1 µF typ) to ground for stability. |
| 2 | GND | power_in | Common ground reference for input and output. Also carries the quiescent current (~2 mA typ, 5.5 mA max). |
| 3 | Input | power_in | Unregulated DC input. Absolute maximum 35 V (Vo≤18V variants). Recommended input capacitor C1=0.33 µF to ground for line-transient rejection. For the 78L12 the recommended operating input range is 14.5 V to 27 V. |

## Key specifications

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

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Output voltage (TJ=25°C) | VO | 11.52 | 12 | 12.48 | V | TJ=25°C | 9 |
| Output voltage | VO | 11.4 |  | 12.6 | V | 14.5V≤VI≤27V,IO=1mA~40mA | 9 |
| Quiescent current | Iq |  |  | 5.5 | mA |  | 9 |
| Quiescent current change (line) | ΔIq |  |  | 15 | mA | 16V≤VI≤27V | 9 |
| Quiescent current change (load) | ΔIq |  |  | 0.1 | mA | 1mA ≤IO≤40mA | 9 |
| Input voltage (for VO=3.3 to 18V) | VI |  |  | 35 | V | for VO=3.3 to 18V | 2 |
| Junction temperature range | TOPR | -20 |  | 120 | °C |  | 2 |
| Storage temperature range | TSTG | -55 |  | 150 | °C |  | 2 |
| Power dissipation (SOT-89) | Pd |  |  | 400 | mW | SOT-89 package | 2 |

## CAD (KiCad official)

- Symbol: `78L12`
- Footprint: `Package_TO_SOT_SMD:SOT-89-3`
- 3D model: SOT-89-3 (KiCad packages3D, STEP)
- 3D model files: `78l12-etched.step` / `78l12-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `78l12.step` / `78l12.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`78l12.step`](78l12.step) | 57 KB | You want the bare part, or you mark your own boards. |
| [`78l12-etched.step`](78l12-etched.step) | 891 KB | You want the part with `78L12` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 242 faces against 42 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:** [UMW datasheet](docs/78l12-datasheet.pdf) (22 pp, sha256 `3eeae843c9f51425`, 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/78l12-datasheet.pdf)