# L79L05ABUTR

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

L79L05ABUTR from STMicroelectronics, in a SOT-89-3. 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 return. Reference for both input and output voltages. On the L79L negative regulator, GND is the most positive terminal in typical operation (VIN and VOUT are both negative with respect to this pin). |
| 2 | VIN | power_in | Unregulated negative DC input. Absolute maximum -30 V for the -5 V version. Bypass to GND with a 0.33 µF capacitor located close to the pin. Note: in SOT-89 the metal tab/heatsink slug is electrically connected to this pin. |
| 3 | VOUT | power_out | Regulated -5 V negative output. Delivers up to 100 mA (internally current-limited, thermally protected). Bypass to GND with a 0.1 µF output capacitor for stability and transient response. |

## Key specifications

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

## Ordering variants

Same part, different packaging or reel option.

- `L79L05ABUTR`
- `L79L05ACUTR`
- `L79L12ACUTR`
- `L79L15ACUTR`
- `L79L05ACZ`
- `L79L05ABZ-AP`
- `L79L08ACZ-AP`
- `L79L05ACZ-TR`
- `L79L12ACZ-TR`
- `L79L05ABD13TR`
- `L79L05ACD13TR`
- `L79L08ACD13TR`
- `L79L12ACD13TR`
- `L79L15ABD13TR`
- `L79L15ACD13TR`

## 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 | -4.8 | -5 | -5.2 | V | TJ = 25 °C | 6 |
| Output voltage | VO | -4.75 |  | -5.25 | V | IO = 1 to 40 mA, VI = -7 to -20 V | 6 |
| Line regulation | ∆VO |  |  | 150 | mV | VI = -7 to -20 V, TJ = 25 °C | 6 |
| Line regulation | ∆VO |  |  | 100 | mV | VI = -8 to -20 V, TJ = 25 °C | 6 |
| Load regulation | ∆VO |  |  | 60 | mV | IO = 1 to 100 mA, TJ = 25 °C | 6 |
| Load regulation | ∆VO |  |  | 30 | mV | IO = 1 to 40 mA, TJ = 25 °C | 6 |
| Quiescent current | Id |  |  | 6 | mA | TJ = 25 °C | 6 |
| Quiescent current | Id |  |  | 5.5 | mA | TJ = 125 °C | 6 |
| Quiescent current change | ∆Id |  |  | 0.1 | mA | IO = 1 to 40 mA | 6 |
| Quiescent current change | ∆Id |  |  | 1.5 | mA | VI = -8 to -20 V | 6 |
| Supply voltage rejection | SVR | 41 | 49 |  | dB | VI = -8 to -18 V, f = 120 Hz, IO = 40 mA, TJ = 25 °C | 6 |
| Dropout voltage | Vd |  |  | 1.7 | V |  | 6 |
| Output noise voltage | eN |  | 40 |  | µV | B = 10 Hz to 100 kHz, TJ = 25 °C | 6 |
| DC input voltage | VI |  |  | -30 | V | VO = -5 to -9 V | 5 |
| Output current | IO |  |  | 100 | mA |  | 5 |
| Storage temperature range | TSTG | -40 |  | 150 | °C |  | 5 |
| Operating junction temperature range | TOP | -40 |  | 125 | °C | For L79L05AB | 5 |
| Thermal resistance junction-case | RthJC |  |  | 15 | °C/W | SOT-89 (column placement to verify) | 5 |
| Thermal resistance junction-ambient | RthJA |  |  | 115 | °C/W | SOT-89 | 5 |

## CAD (KiCad official)

- Symbol: `L79L05ABUTR`
- Footprint: `Package_TO_SOT_SMD:SOT-89-3`
- 3D model: SOT-89-3 (KiCad packages3D, STEP)
- 3D model files: `l79l05abutr-etched.step` / `l79l05abutr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `l79l05abutr.step` / `l79l05abutr.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`l79l05abutr.step`](l79l05abutr.step) | 57 KB | You want the bare part, or you mark your own boards. |
| [`l79l05abutr-etched.step`](l79l05abutr-etched.step) | 1.5 MB | You want the part with `L79L05ABUTR` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 388 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:** [STMicroelectronics datasheet](https://www.st.com/resource/en/datasheet/l79l05abutr.pdf) (24 pp, sha256 `ba2a02bb5533f64a`, retrieved 2026-08-17, tier: manufacturer)
- **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/l79l05abutr-datasheet.pdf)