# LM3409QMYX

**Texas Instruments** · LED Drivers · HVSSOP-10-EP-0.5mm

LM3409QMYX from Texas Instruments, in a HVSSOP-10-EP-0.5mm. 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 | UVLO | input | Input undervoltage lockout pin: connect to a resistor divider from VIN and GND; turn-on threshold is 1.24 V and turn-off hysteresis is provided by a 22 µA current source. |
| 2 | IADJ | input | Analog LED current adjust: apply 0 to 1.24 V, connect a resistor to GND, or leave open to set the current sense threshold voltage (IADJ current limited to ±5 mA continuous). |
| 3 | EN | input | Logic-level enable and PWM dimming input: a voltage above 1.74 V enables the device, a PWM signal dims it, and a voltage below 0.5 V selects low-power shutdown. |
| 4 | COFF | passive | Off-time programming pin: connect a resistor from VO and a capacitor to GND to set the off-time; COFF is rated -0.3 V to 4 V to GND with ±1 mA continuous current. |
| 5 | GND | power_in | System ground; connect to system ground. |
| 6 | PGATE | output | Gate drive output: connect to the gate of the external P-channel MOSFET; VIN to PGATE is rated -0.3 V to 7 V (9.5 V maximum for 100 ns). |
| 7 | CSN | input | Negative current sense input: connect to the negative side of the sense resistor, with VIN to CSN limited to -0.3 V to 0.3 V. |
| 8 | CSP | input | Positive current sense input: connect to the positive side of the sense resistor and also to VIN, with VIN to CSP limited to -0.3 V to 0.3 V. |
| 9 | VCC | power_out | VIN-referenced linear regulator output providing P-channel MOSFET drive power: connect at least a 1 µF ceramic capacitor to VIN; VIN to VCC is rated -0.3 V to 7 V. |
| 10 | VIN | power_in | Input voltage: connect to the input supply; for the LM3409-Q1 this is rated 6 V to 42 V. |
| 11 | DAP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | HVSSOP-10-EP-0.5mm |
| Category | LED Drivers |
| Pins | 11 |

## CAD (KiCad official)

- Symbol: `LM3409QMYX`
- Footprint: `Package_SO:MSOP-10-1EP_3x3mm_P0.5mm_EP1.68x1.88mm`
- 3D model: HVSSOP-10-EP-0.5mm (KiCad packages3D, STEP)
- 3D model files: `lm3409qmyx-etched.step` / `lm3409qmyx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm3409qmyx.step` / `lm3409qmyx.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/lm3409-q1) (47 pp, sha256 `7745578a43302ee7`, retrieved 2026-10-08, 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/lm3409qmyx-datasheet.pdf)