# LM3445MMX

**Texas Instruments** · LED Drivers · VSSOP-10-0.5mm

LM3445MMX from Texas Instruments, in a VSSOP-10-0.5mm. 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 | ASNS | output | PWM output of TRIAC dim decoder circuit with 0-4 V range; duty cycle proportional to dimmer on-time. |
| 2 | FLTR1 | input | First filter input; 120-Hz PWM signal compared to 1-3 V, 5.85-kHz ramp to generate proportional frequency PWM. |
| 3 | DIM | bidirectional | Input/output dual function dim pin; can be driven with external PWM or used as output to other drivers; pull above 4.9 V to tri-state. |
| 4 | COFF | input | OFF time setting pin; user-set RC network connected to this pin sets constant OFF time of switching controller. |
| 5 | FLTR2 | input | Second filter input; capacitor filters PWM dimming signal to provide DC voltage for LED current control or analog dimming. |
| 6 | GND | power_in | Circuit ground connection and power return path. |
| 7 | ISNS | input | LED current sense input; external resistor from MOSFET source to GND through this pin sets maximum LED current. |
| 8 | GATE | output | Power MOSFET driver output; provides gate drive for power switching MOSFET of buck controller. |
| 9 | VCC | power_in | Input voltage pin; supplies 8-12 V to internal control circuitry and gate driver. |
| 10 | BLDR | input | Bleeder pin with internal switched 230-Ω resistor; provides input path and current for proper TRIAC dimmer firing. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | VSSOP-10-0.5mm |
| Category | LED Drivers |
| Pins | 10 |

## CAD (KiCad official)

- Symbol: `LM3445MMX`
- Footprint: `Package_SO:MSOP-10_3x3mm_P0.5mm`
- 3D model: VSSOP-10-0.5mm (KiCad packages3D, STEP)
- 3D model files: `lm3445mmx-etched.step` / `lm3445mmx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm3445mmx.step` / `lm3445mmx.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/lm3445) (46 pp, sha256 `e690e402245bfa5e`, 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/lm3445mmx-datasheet.pdf)