# A1123LLHLX-T

**Allegro MicroSystems, LLC** · Magnetic Sensors · SOT-23W

A1123LLHLX-T from Allegro MicroSystems, LLC, in a SOT-23W. 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 | VCC | power_in | Connects the power supply to the chip; forward supply voltage is 3 to 24 V in operation (TJ < 165°C), with an absolute maximum forward supply voltage of 26.5 V. |
| 2 | VOUT | output | Short-circuit-protected open-drain output that sinks up to 25 mA continuous, with an output off voltage rating of 26 V maximum. |
| 3 | GND | power_in | Ground connection for the device. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Allegro MicroSystems, LLC |
| Package | SOT-23W |
| Category | 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 |
|---|---|---|---|---|---|---|---|
| Forward Supply Voltage | VCC |  |  | 26.5 | V |  | 3 |
| Reverse Supply Voltage | VRCC | -30 |  |  | V |  | 3 |
| Output Off Voltage | VOUT |  |  | 26 | V |  | 3 |
| Continuous Output Current | IOUT |  |  | 25 | mA |  | 3 |
| Reverse Output Current | IROUT | -50 |  |  | mA |  | 3 |
| Operating Ambient Temperature, Range L | TA | -40 |  | 150 | °C | Range L | 3 |
| Maximum Junction Temperature | TJ(max) |  |  | 165 | °C |  | 3 |
| Storage Temperature | Tstg | -65 |  | 170 | °C |  | 3 |
| Forward Supply Voltage | VCC | 3 |  | 24 | V | Operating, TJ < 165°C | 4 |
| Output Leakage Current (A1123) | IOUTOFF |  |  | 10 | µA | VOUT = 24 V, B < BRP | 4 |
| Output Saturation Voltage (A1123) | VOUT(SAT) |  | 185 | 500 | mV | IOUT = 20 mA, B > BOP | 4 |
| Output Current Limit (A1123) | IOM | 30 |  | 60 | mA | B > BOP | 4 |
| Power-On Time | tPO |  |  | 25 | µs | VCC > 3.0 V, B < BRP(min), 10 G, B > BOP(max) + 10 G | 4 |
| Output Rise Time | tr |  | 0.2 | 2 | µs | RL = 820 Ω, CS = 20 pF | 4 |
| Output Fall Time | tf |  | 0.1 | 2 | µs | RL = 820 Ω, CS = 20 pF | 4 |
| Supply Current, On (A1123) | ICC(ON) |  |  | 4 | mA | VCC = 12 V, B > BOP | 4 |
| Supply Current, Off (A1123) | ICC(OFF) |  |  | 4 | mA | VCC = 12 V, B < BRP | 4 |
| Reverse Supply Current | IRCC |  |  | -5 | mA | VRCC = -30 V | 4 |
| Supply Zener Clamp Voltage | VZ | 28 |  |  | V | ICC = 5 mA; TA = 25°C | 4 |
| Operate Point (A1123) | BOP | 205 | 280 | 355 | G |  | 5 |
| Release Point (A1123) | BRP | 150 | 225 | 300 | G |  | 5 |
| Hysteresis (A1123) | BHYS | 30 | 55 | 80 | G |  | 5 |
| Package Thermal Resistance, LH 1-layer PCB | RθJA |  | 228 |  | °C/W | Package LH, 1-layer PCB with copper limited to solder pads | 6 |
| Package Thermal Resistance, LH 2-layer PCB | RθJA |  | 110 |  | °C/W | Package LH, 2-layer PCB with 0.463 in.2 of copper area each side connected by thermal vias | 6 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts |  | tin | SIP for through-hole mounting. Each package type is lead (Pb) free (suffix, -T), with a 100% matte-tin-plated leadframe. | 1 |

## CAD (KiCad official)

- Symbol: `A1123LLHLX-T`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23W (KiCad packages3D, STEP)
- 3D model files: `a1123llhlx-t-etched.step` / `a1123llhlx-t-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `a1123llhlx-t.step` / `a1123llhlx-t.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Allegro MicroSystems, LLC datasheet](docs/a1123llhlx-t-datasheet.pdf) (18 pp, sha256 `2e2d51c564dee4c6`, retrieved 2026-10-30, tier: lcsc)
- **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/a1123llhlx-t-datasheet.pdf)