# 79L12

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

79L12 from TWGMC, 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 | GND | power_in | Ground / common reference pin. Common return for input and output; for a negative regulator this pin is the most-positive terminal. |
| 2 | IN | power_in | Unregulated negative input voltage. Absolute max Vi = -35 V; typical operating range -14.5 V to -27 V. Bypass with a 0.33 uF capacitor (Ci) close to the pin. |
| 3 | OUT | power_out | Regulated -12 V output (typ). Delivers up to 100 mA (IOM 0.1 A). Bypass with a 0.1 uF capacitor (Co) close to the pin for optimum stability and transient response. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | TWGMC |
| Package | SOT-89 |
| 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 | Vo | -11.5 | -12 | -12.5 | V | 25℃ | 1 |
| Output Voltage | Vo | -11.4 | -12 | -12.6 | V | -14.5V≤Vl≤-27V, Io=1mA~40mA | 1 |
| Load Regulation | ΔVo |  | 24 | 100 | mV | Io=1mA~100mA, 25℃ | 1 |
| Load Regulation | ΔVo |  | 15 | 50 | mV | Io=1mA~40mA, 25℃ | 1 |
| Line Regulation | ΔVo |  | 50 | 250 | mV | -14.5V≤Vl≤-27V, 25℃ | 1 |
| Line Regulation | ΔVo |  | 40 | 200 | mV | -16V≤Vl≤-27V, 25℃ | 1 |
| Quiescent Current | Iq |  |  | 6.5 | mA | 25℃ | 1 |
| Quiescent Current Change | ΔIq |  |  | 1.5 | mA | -16V≤Vl≤-27V, 0-125℃ | 1 |
| Quiescent Current Change | ΔIq |  |  | 0.1 | mA | 1mA≤IO≤40mA, 0-125℃ | 1 |
| Output Noise Voltage | VN |  |  | 80 | μV | 10Hz≤f≤100KHz, 25℃ | 1 |
| Ripple Rejection | RR | 37 | 42 |  | dB | -15V≤Vl≤-25V, f=120Hz, 0-125℃ | 1 |
| Dropout Voltage | Vd |  |  | 1.7 | V | 25℃ | 1 |
| Input Voltage | Vl | -35 |  |  | V |  | 1 |
| Operating Junction Temperature Range | TOPR | 0 |  | 150 | ℃ |  | 1 |
| Storage Temperature Range | TSTG | -55 |  | 150 | ℃ |  | 1 |
| Maximum Output Current | IOM |  |  | 0.1 | A |  | 1 |

## CAD (KiCad official)

- Symbol: `79L12`
- Footprint: `Package_TO_SOT_SMD:SOT-89-3`
- 3D model: SOT-89 (KiCad packages3D, STEP)
- 3D model files: `79l12-etched.step` / `79l12-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `79l12.step` / `79l12.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`79l12.step`](79l12.step) | 57 KB | You want the bare part, or you mark your own boards. |
| [`79l12-etched.step`](79l12-etched.step) | 820 KB | You want the part with `79L12` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 227 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:** [TWGMC datasheet](docs/79l12-datasheet.pdf) (2 pp, sha256 `c1a0d6c49d6d3487`, 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/79l12-datasheet.pdf)