# L78L05ACUTR

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

L78L05ACUTR 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 | VOUT | power_out | Regulated +5 V output. Delivers up to 100 mA of load current. Bypass to GND with a 0.1 uF (or larger) ceramic capacitor per ST's recommended application. |
| 2 | GND | power_in | Ground / common reference for both input and output. On the SOT-89 this pin also functions as the die-attach tab used for heat-sinking to the PCB copper. |
| 3 | VIN | power_in | Unregulated DC input supply. Absolute maximum 30 V for the 5 V variant; typical operating range roughly 7-20 V. Bypass to GND with a 0.33 uF (or larger) capacitor located close to the pin. |

## Key specifications

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

## Ordering variants

Same part, different packaging or reel option.

- `L78L05ACUTR`
- `L78L05ABUTR`
- `L78L05ACZ`
- `L78L05ACZ-AP`
- `L78L05ACZ-TR`
- `L78L05ABZ`
- `L78L05ABZ-AP`
- `L78L05ABZ-TR`
- `L78L05CZ`
- `L78L05ABD13TR`
- `L78L05ACD13TR`
- `L78L05CD13TR`

## 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 | 16 |
| Output voltage | VO | 4.75 |  | 5.25 | V | IO = 1 to 40 mA, VI = 7 to 20 V | 16 |
| Line regulation | ΔVO |  |  | 150 | mV | VI = 7 to 20 V, TJ = 25 °C | 16 |
| Line regulation | ΔVO |  |  | 100 | mV | VI = 8 to 20 V, TJ = 25 °C | 16 |
| Load regulation | ΔVO |  |  | 60 | mV | IO = 1 to 100 mA, TJ = 25 °C | 16 |
| Load regulation | ΔVO |  |  | 30 | mV | IO = 1 to 40 mA, TJ = 25 °C | 16 |
| Quiescent current | Id |  |  | 6 | mA | TJ = 25 °C | 16 |
| Quiescent current | Id |  |  | 5.5 | mA | TJ = 125 °C | 16 |
| Quiescent current change | ΔId |  |  | 0.1 | mA | IO = 1 to 40 mA | 16 |
| Quiescent current change | ΔId |  |  | 1.5 | mA | VI = 8 to 20 V | 16 |
| Output noise voltage | eN |  |  | 40 | µV | B = 10 Hz to 100 kHz, TJ = 25 °C | 16 |
| Supply voltage rejection | SVR | 41 | 49 |  | dB | VI = 8 to 18 V, f = 120 Hz, IO = 40 mA, TJ = 25 °C | 16 |
| Dropout voltage | Vd |  |  | 1.7 | V |  | 16 |
| DC input voltage (VO = 3.3 to 9 V; applies to 5 V output) | VI |  |  | 30 | V | VO = 3.3 to 9 V | 5 |
| Output current | IO |  |  | 100 | mA |  | 5 |
| Storage temperature range | TSTG | -65 |  | 150 | °C |  | 5 |
| Operating junction temperature range (L78LxxAC / L78LxxC) | TOP | 0 |  | 125 | °C | for L78LxxAC / L78LxxC | 5 |
| Thermal resistance junction-ambient (SOT-89) | RthJA |  |  | 55 | °C/W | Considering 6 cm² of copper board heat-sink (note 1) | 5 |

## CAD (KiCad official)

- Symbol: `L78L05ACUTR`
- Footprint: `Package_TO_SOT_SMD:SOT-89-3`
- 3D model: SOT-89-3 (KiCad packages3D, STEP)
- 3D model files: `l78l05acutr-etched.step` / `l78l05acutr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `l78l05acutr.step` / `l78l05acutr.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`l78l05acutr.step`](l78l05acutr.step) | 57 KB | You want the bare part, or you mark your own boards. |
| [`l78l05acutr-etched.step`](l78l05acutr-etched.step) | 1.5 MB | You want the part with `L78L05ACUTR` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 396 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/l78l05acutr.pdf) (47 pp, sha256 `08da79fddb104256`, 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/l78l05acutr-datasheet.pdf)