# LM3405AXMY

**Texas Instruments** · LED Drivers · MSOP-8-EP

LM3405AXMY from Texas Instruments, in a MSOP-8-EP. 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 | FB | input | Feedback pin; connect to LED string cathode and external resistor to ground to set LED current. |
| 2 | GND | power_in | Signal and power ground pin; place feedback network resistor as close as possible to this pin. |
| 3 | NC | unconnected | No connection. |
| 4 | BOOST | output | Boost voltage output to drive NMOS switch; connect bootstrap capacitor between BOOST and SW pins. |
| 5 | SW | output | Switch pin; connect to inductor, catch diode, and bootstrap capacitor. |
| 6 | VIN | power_in | Input supply voltage from 3 V to 22 V; connect bypass capacitor locally to ground. |
| 7 | GND | power_in | Signal and power ground pin; place feedback network resistor as close as possible to this pin. |
| 8 | EN/DIM | input | Enable/dim control input; logic high enables operation, toggling controls LED brightness; do not allow to float or exceed VIN + 0.3 V. |
| 9 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | MSOP-8-EP |
| Category | LED Drivers |
| Pins | 9 |

## CAD (KiCad official)

- Symbol: `LM3405AXMY`
- Footprint: `Package_SO:MSOP-8-1EP_3x3mm_P0.65mm_EP1.5x1.8mm`
- 3D model: MSOP-8-EP (KiCad packages3D, STEP)
- 3D model files: `lm3405axmy-etched.step` / `lm3405axmy-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm3405axmy.step` / `lm3405axmy.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/cn/lit/gpn/lm3405a) (37 pp, sha256 `6ffca81b353b1a67`, retrieved 2026-10-07, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-4-5-20251001` (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/lm3405axmy-datasheet.pdf)