# X252040MMB4SI

**Yangxing Tech** · Crystals · SMD2520-4P

X252040MMB4SI from Yangxing Tech, in a SMD2520-4P. 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 | XTAL1 | passive | Crystal terminal #1, one of the two diagonal crystal connections shown on the Top View Crystal Connection drawing. |
| 2 | GND | power_in | Marked GND on the recommended land pattern (Top View Crystal Connection); ground/case connection. |
| 3 | XTAL2 | passive | Crystal terminal #3, the other diagonal crystal connection, opposite pin 1. |
| 4 | GND | power_in | Marked GND on the recommended land pattern (Top View Crystal Connection); ground/case connection. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Yangxing Tech |
| Package | SMD2520-4P |
| Category | Crystal Oscillator/Oscillator/Resonator |
| Pins | 4 |

## CAD (KiCad official)

- Symbol: `X252040MMB4SI`
- Footprint: `Crystal:Crystal_SMD_2520-4Pin_2.5x2.0mm`
- 3D model: SMD2520-4P (KiCad packages3D, STEP)
- 3D model files: `x252040mmb4si-etched.step` / `x252040mmb4si-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `x252040mmb4si.step` / `x252040mmb4si.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Yangxing Tech datasheet](docs/x252040mmb4si-datasheet.pdf) (1 pp, sha256 `fcfea8bbb6808668`, retrieved 2026-10-21, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (vision), consensus `claude-opus-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/x252040mmb4si-datasheet.pdf)