# LMR61428XMMX

**Texas Instruments** · DC-DC Converters · VSSOP-8-0.65mm

LMR61428XMMX from Texas Instruments, in a VSSOP-8-0.65mm. 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 | PGND | power_in | Power ground return for power stage circuits. |
| 2 | EN | input | Active-low shutdown input; regulator disabled below 0.15×VDD, enabled above 0.7×VDD; absolute maximum rating -0.5V to 10V. |
| 3 | FREQ | input | Frequency programming input; external resistor connected between FREQ and VDD sets switching frequency from 300kHz to 2MHz; 100µA maximum current rating. |
| 4 | FB | input | Output voltage feedback input from resistor divider for regulated output voltage 1.24V to 14V; typical pin voltage 1.24V; absolute maximum rating -0.5V to 10V. |
| 5 | SGND | power_in | Signal ground for feedback and control circuits. |
| 6 | VDD | power_in | Power supply input for internal control circuitry; operating range 2.5V to 5V; absolute maximum rating -0.5V to 10V. |
| 7 | BOOT | power_in | Bootstrap supply input for MOSFET gate driver; operating range 0V to 10V; absolute maximum rating -0.5V to 10V. |
| 8 | SW | output | Drain of internal N-channel MOSFET power switch; boost converter switching node connecting to inductor and freewheeling diode; absolute maximum rating -0.5V to 14.5V with 2.85A peak switch current limit. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | VSSOP-8-0.65mm |
| Category | Power Supply Chip |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `LMR61428XMMX`
- Footprint: `Package_SO:VSSOP-8_2.3x2mm_P0.5mm`
- 3D model: VSSOP-8-0.65mm (KiCad packages3D, STEP)
- 3D model files: `lmr61428xmmx-etched.step` / `lmr61428xmmx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lmr61428xmmx.step` / `lmr61428xmmx.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/lmr61428) (22 pp, sha256 `d55e65d8766ee830`, 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/lmr61428xmmx-datasheet.pdf)