# AO4421

**Alpha Omega Semicon** · MOSFETs · SOIC-8

AO4421 from Alpha Omega Semicon, in a SOIC-8. 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 | S | passive | Source of the P-channel MOSFET, one of three parallel source pins; drain-source voltage rated -60V. |
| 2 | S | passive | Source of the P-channel MOSFET, one of three parallel source pins; continuous drain current -6.2A at TA=25°C. |
| 3 | S | passive | Source of the P-channel MOSFET, one of three parallel source pins; body diode continuous current 4.2A max. |
| 4 | G | input | Gate of the P-channel MOSFET; gate-source voltage limited to ±20V, threshold -1V to -3V at ID=-250µA. |
| 5 | D | passive | Drain of the P-channel MOSFET, one of four parallel drain pins; drain-source voltage rated -60V. |
| 6 | D | passive | Drain of the P-channel MOSFET, one of four parallel drain pins; pulsed drain current -40A max. |
| 7 | D | passive | Drain of the P-channel MOSFET, one of four parallel drain pins; RDS(ON) under 40mΩ at VGS=-10V. |
| 8 | D | passive | Drain of the P-channel MOSFET, one of four parallel drain pins; RDS(ON) under 50mΩ at VGS=-4.5V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Alpha Omega Semicon |
| Package | SOIC-8 |
| Category | Transistors/Thyristors |
| Pins | 8 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| BVDSS Drain-Source Breakdown Voltage | BVDSS | -60 |  |  | V | ID=-250µA, VGS=0V | 2 |
| Zero Gate Voltage Drain Current (TJ=25°C) | IDSS |  |  | -1 | µA | VDS=-48V, VGS=0V | 2 |
| Zero Gate Voltage Drain Current (TJ=55°C) | IDSS |  |  | -5 | µA | VDS=-48V, VGS=0V, TJ=55°C | 2 |
| Gate-Body leakage current | IGSS | -100 |  | 100 | nA | VDS=0V, VGS=±20V | 2 |
| Gate Threshold Voltage | VGS(th) | -1 | -2 | -3 | V | VDS=VGS, ID=-250µA | 2 |
| On state drain current | ID(ON) | -40 |  |  | A | VGS=-10V, VDS=-5V | 2 |
| Static Drain-Source On-Resistance | RDS(ON) |  | 32 | 40 | mΩ | VGS=-10V, ID=-6.2A | 2 |
| Static Drain-Source On-Resistance (TJ=125°C) | RDS(ON) |  | 53 | 70 | mΩ | VGS=-10V, ID=-6.2A, TJ=125°C | 2 |
| Static Drain-Source On-Resistance | RDS(ON) |  | 40 | 50 | mΩ | VGS=-4.5V, ID=-5A | 2 |
| Diode Forward Voltage | VSD |  | -0.74 | -1 | V | IS=-1A, VGS=0V | 2 |
| Maximum Body-Diode Continuous Current | IS |  |  | -4.2 | A |  | 2 |
| Input Capacitance | Ciss |  | 2417 | 2900 | pF | VGS=0V, VDS=-30V, f=1MHz | 2 |
| Gate resistance | Rg |  | 1.9 | 2.3 | Ω | VGS=0V, VDS=0V, f=1MHz | 2 |
| Total Gate Charge (10V) | Qg |  | 46.5 | 55 | nC | VGS=-10V, VDS=-30V, ID=-6.2A | 2 |
| Body Diode Reverse Recovery Time | trr |  | 34 | 42 | ns | IF=-6.2A, dI/dt=100A/µs | 2 |
| Drain-Source Voltage | VDS |  |  | -60 | V |  | 1 |
| Gate-Source Voltage | VGS | -20 |  | 20 | V |  | 1 |
| Continuous Drain Current | ID |  |  | -6.2 | A | TA=25°C | 1 |
| Continuous Drain Current | ID |  |  | -5 | A | TA=70°C | 1 |
| Pulsed Drain Current | IDM |  |  | -40 | A |  | 1 |
| Power Dissipation | PD |  |  | 3.1 | W | TA=25°C | 1 |
| Power Dissipation | PD |  |  | 2 | W | TA=70°C | 1 |
| Junction and Storage Temperature Range | TJ, TSTG | -55 |  | 150 | °C |  | 1 |
| Maximum Junction-to-Ambient (t ≤ 10s) | RθJA |  | 24 | 40 | °C/W | t ≤ 10s | 1 |
| Maximum Junction-to-Ambient (Steady-State) | RθJA |  | 54 | 75 | °C/W | Steady-State | 1 |
| Maximum Junction-to-Lead (Steady-State) | RθJL |  | 21 | 30 | °C/W | Steady-State | 1 |

## CAD (KiCad official)

- Symbol: `AO4421`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `ao4421-etched.step` / `ao4421-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ao4421.step` / `ao4421.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Alpha Omega Semicon datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8586184817456766976) (4 pp, sha256 `8ba23a9b5c529b1c`, retrieved 2026-10-09, 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/ao4421-datasheet.pdf)