# LD1117AG-25-AA3-A-R

**UTC Unisonic Tech** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · SOT-223-4

LD1117AG-25-AA3-A-R from UTC Unisonic Tech, in a SOT-223-4. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | GND | power_in | Ground reference pin (marked GND/ADJ; GND on this fixed 2.5V version), pin assignment code A. |
| 2 | VOUT | power_out | Regulated 2.5V output (2.450 to 2.550V at 25°C), with up to 1A output current for the LD1117A and internal current limit and over-temperature protection. |
| 3 | VIN | power_in | Input supply voltage, recommended maximum 15V and absolute maximum 18V. |
| 4 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | UTC Unisonic Tech |
| Package | SOT-223-4 |
| Category | Power Management (PMIC) |
| Pins | 4 |

## 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 | VOUT | 2.45 | 2.5 | 2.55 | V | VIN=4.5V, IOUT=10mA, TJ=25°C | 6 |
| Line Regulation | VOUT |  | 1 | 6 | mV | VIN=3.9 to 10V, IOUT=0mA | 6 |
| Load Regulation | VOUT |  | 1 | 10 | mV | VIN=3.9V, LD1117A: IOUT=0~1000mA | 6 |
| Quiescent Current | IQ |  | 5 | 10 | mA | VIN10V | 6 |
| Supply Voltage Rejection | SVR | 60 | 75 |  | dB | IOUT=40mA, f=120Hz, TJ=25°C, VIN=5.5V, VRIPPLE=1VPP | 6 |
| Dropout Voltage | VD |  | 1 | 1.1 | V | IOUT=100mA | 6 |
| Dropout Voltage | VD |  | 1.15 | 1.25 | V | IOUT=500mA | 6 |
| Dropout Voltage | VD |  | 1.2 | 1.3 | V | IOUT=800mA | 6 |
| Thermal Regulation |  |  | 0.01 | 0.1 | %/W | TA=25°C, 30ms Pulse | 6 |
| Input Voltage (recommended) | VIN |  |  | 15 | V |  | 4 |
| Operating Junction Temperature | TJ | -20 |  | 125 | °C |  | 4 |
| DC Input Voltage | VIN |  |  | 18 | V |  | 4 |
| Junction Temperature | TJ |  |  | 150 | °C |  | 4 |
| Operating Temperature | TOPR | -20 |  | 125 | °C | Note 2: determined from design only, not 100% tested in mass production | 4 |
| Storage Temperature | TSTG | -65 |  | 150 | °C |  | 4 |
| Junction to Ambient, SOT-223 | θJA |  | 165 |  | °C/W |  | 4 |
| Junction to Case, SOT-223 | θJC |  | 15 |  | C/W |  | 4 |

## CAD (KiCad official)

- Symbol: `LD1117AG-25-AA3-A-R`
- Footprint: `Package_TO_SOT_SMD:SOT-223`
- 3D model: SOT-223-4 (KiCad packages3D, STEP)
- 3D model files: `ld1117ag-25-aa3-a-r-etched.step` / `ld1117ag-25-aa3-a-r-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ld1117ag-25-aa3-a-r.step` / `ld1117ag-25-aa3-a-r.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [UTC Unisonic Tech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8586175467829673984) (15 pp, sha256 `f7f26a117cb07dc2`, retrieved 2026-10-18, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/ld1117ag-25-aa3-a-r-datasheet.pdf)