# LM3404B

**Leiditech** · MOSFETs · SOT-23

LM3404B from Leiditech, in a SOT-23. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | G | input | Gate. Control terminal for the N-channel enhancement mode MOSFET. VGS(th) typ 1.5V (1.2V min / 2.5V max at VDS=VGS, ID=250μA). Absolute maximum VGSS = ±20V. Rated for full enhancement at VGS=10V (RDS(on) typ 29mΩ) and logic-level operation at VGS=4.5V (RDS(on) typ 45mΩ). |
| 2 | S | passive | Source. Reference terminal for gate drive and current return for the drain-source channel. Continuous drain-to-source diode forward current IS = 4A max; body diode VSD = 1.2V max at IS=4A, VGS=0V. |
| 3 | D | passive | Drain. Switched high-side terminal of the N-channel MOSFET. VDSS = 30V max (V(BR)DSS typ 32V at VGS=0V, ID=250μA). Continuous drain current ID = 4.2A at TA=25℃ (2.6A at TA=70℃); pulsed IDM = 16A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Leiditech |
| Package | SOT-23 |
| Category | Transistors/Thyristors |
| Pins | 3 |

## Ordering variants

Same part, different packaging or reel option.

- `LM3404B`

## 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 Voltage | VDSS |  |  | 30 | V |  | 1 |
| Gate-Source Voltage | VGSS | -20 |  | 20 | V |  | 1 |
| Continuous Drain Current | ID |  |  | 4.2 | A | TA=25℃ | 1 |
| Continuous Drain Current | ID |  |  | 2.6 | A | TA=70℃ | 1 |
| Pulsed Drain Current | IDM |  |  | 16 | A |  | 1 |
| Power Dissipation | PD |  |  | 1 | W | TA = 25℃ | 1 |
| Thermal Resistance, Junction to Ambient | RθJA |  |  | 125 | ℃/W |  | 1 |
| Operating and Storage Temperature Range | TJ, TSTG | -55 |  | 150 | ℃ |  | 1 |
| Drain-Source Breakdown Voltage | V(BR)DSS | 30 | 32 |  | V | VGS=0V, ID=250μA | 2 |
| Zero Gate Voltage Drain Current | IDSS |  |  | 1 | μA | VDS=30V, VGS=0V | 2 |
| Gate to Body Leakage Current | IGSS | -100 |  | 100 | nA | VDS=0V, VGS= ±20V | 2 |
| Gate Threshold Voltage | VGS(th) | 1.2 | 1.5 | 2.5 | V | VDS=VGS, ID=250μA | 2 |
| Static Drain-Source on-Resistance | RDS(on) |  | 29 | 38 | mΩ | VGS=10V, ID=4A | 2 |
| Static Drain-Source on-Resistance | RDS(on) |  | 45 | 65 | mΩ | VGS=4.5V, ID=3A | 2 |
| Maximum Continuous Drain to Source Diode Forward Current | IS |  |  | 4 | A |  | 2 |
| Maximum Pulsed Drain to Source Diode Forward Current | ISM |  |  | 16 | A |  | 2 |
| Drain to Source Diode Forward Voltage | VSD |  |  | 1.2 | V | VGS=0V, IS=4A | 2 |

## CAD (KiCad official)

- Symbol: `LM3404B`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `lm3404b-etched.step` / `lm3404b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm3404b.step` / `lm3404b.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Leiditech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603039826593656832) (None pp, sha256 `2db1e81a6605a692`, retrieved 2026-08-17, tier: lcsc)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/lm3404b-datasheet.pdf)