# DO4085A

**DOINGTER** · MOSFETs · SOT-23

DO4085A from DOINGTER, in a SOT-23. 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 | G | input | Gate; gate-source voltage limited to ±20 V, with threshold VGS(th) of -1.2 V min to -2.5 V max at 250 µA. |
| 2 | D | passive | Drain; drain-source voltage rated -40 V with continuous drain current of -5 A at TA=25°C and pulsed -20 A. |
| 3 | S | passive | Source of the P-channel MOSFET; body diode continuous current IS is -4.2 A max. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | DOINGTER |
| Package | SOT-23 |
| Category | Transistors/Thyristors |
| 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 |
|---|---|---|---|---|---|---|---|
| Drain-Source Breakdown Voltage | BVDSS | -40 |  |  | V | VGS=0V,ID=250μA | 2 |
| Zero Gate Voltage Drain Current | IDSS |  |  | -1 | μA | VGS=0V, VDS=-40V | 2 |
| Gate-Source Leakage Current | IGSS | -100 |  | 100 | nA | VGS=±20V, VDS=0A | 2 |
| Gate-Source Threshold Voltage | VGS(th) | -1.2 | -1.6 | -2.5 | V | VGS=VDS, ID=250μA | 2 |
| Drain-Source On Resistance | RDS(ON) |  | 60 | 78 | mΩ | VGS=-10V,ID=-3A | 2 |
| Drain-Source On Resistance | RDS(ON) |  | 71 | 100 | mΩ | VGS=-4.5V,ID=-2A | 2 |
| Diode Forward Voltage | VSD |  |  | -1.2 | V | VGS=0V, ISD=-5A | 2 |
| Continuous Drain Current (diode) | IS |  |  | -4.2 | A | VD=VG=0V | 2 |
| Pulsed Drain Current (diode) | ISM |  |  | -16.6 | A |  | 2 |
| Drain-Source Voltage | VDS |  |  | -40 | V |  | 1 |
| Gate-Source Voltage | VGS | -20 |  | 20 | V |  | 1 |
| Continuous Drain Current | ID |  |  | -5 | A | TA=25℃ | 1 |
| Continuous Drain Current | ID |  |  | -2.5 | A | TA=100℃ | 1 |
| Pulsed Drain Current | IDM |  |  | -20 | A |  | 1 |
| Power Dissipation | PD |  |  | 1.5 | W |  | 1 |
| Operating and Storage Junction Temperature Range | TJ, TSTG | -55 |  | 150 | ℃ |  | 1 |
| Thermal Resistance, Junction to Ambient | RθJA |  |  | 82 | ℃/W |  | 1 |

## CAD (KiCad official)

- Symbol: `DO4085A`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `do4085a-etched.step` / `do4085a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `do4085a.step` / `do4085a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [DOINGTER datasheet](docs/do4085a-datasheet.pdf) (7 pp, sha256 `388ec176904657d7`, retrieved 2026-10-17, 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/do4085a-datasheet.pdf)