# HAL251ST

**Hallwee** · Hall Switches · TSOT-23-3L

HAL251ST from Hallwee, in a TSOT-23-3L. 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 | VDD | power_in | Supply voltage pin (电源电压引脚); the datasheet gives an operating supply of 1.65 V to 5.5 V and an absolute maximum VDD of 6 V. |
| 2 | GND | power_in | Ground pin (接地引脚) for the device. |
| 3 | OUT | output | Push-pull output pin (推挽式输出引脚); the absolute maximum output voltage is 5 V and the absolute maximum output current is 10 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Hallwee |
| Package | TSOT-23-3L |
| Category | Magnetic Sensors |
| 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 |
|---|---|---|---|---|---|---|---|
| Working voltage (VDD) | VDD | 1.65 | 3 | 5.5 | V |  | 2 |
| Supply current, average (operating) | IDD |  | 5 |  | uA | 工作时 平均值 (operating, average) | 2 |
| Output current | IOUT |  | 3 |  | mA |  | 2 |
| Saturation voltage | VSAT |  |  | 0.4 | V | IOUT=1mA | 2 |
| Awake mode time | TAW |  | 80 |  | uS | VDD=2.75V, internal clock diagram (page 3) | 3 |
| Sleep mode time | TSL |  | 80 |  | mS | VDD=2.75V, internal clock diagram (page 3) | 3 |
| Operating point | BOP | 30 |  | 55 | GS | TA=25℃, VDD=3V | 3 |
| Release point | BRP | 10 |  | 20 | GS | TA=25℃, VDD=3V | 3 |
| Hysteresis | BHYS |  | 10 |  | GS | TA=25℃, VDD=3V | 3 |
| Supply voltage (operating) | VDD |  |  | 6 | V |  | 2 |
| Supply current | IDD |  |  | 7 | mA |  | 2 |
| Output voltage | VOUT |  |  | 5 | V |  | 2 |
| Output current | IOUT |  |  | 10 | mA |  | 2 |
| Operating temperature range | TA | -40 |  | 85 | ℃ |  | 2 |
| Storage temperature range | TS | -65 |  | 150 | ℃ |  | 2 |
| ESD withstand voltage | VESD |  |  | 4 | KV |  | 2 |

## CAD (KiCad official)

- Symbol: `HAL251ST`
- Footprint: `Package_TO_SOT_SMD:SOT-23-3`
- 3D model: TSOT-23-3L (KiCad packages3D, STEP)
- 3D model files: `hal251st-etched.step` / `hal251st-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `hal251st.step` / `hal251st.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Hallwee datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8602971803702870016) (4 pp, sha256 `c2a4502611d74559`, retrieved 2026-10-19, tier: lcsc)
- **Datasheet language:** Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-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/hal251st-datasheet.pdf)