# SX25Y040000B91T001

**TKD** · Crystals · SMD2520-4P

SX25Y040000B91T001 from TKD, 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 connected to the quartz blank (pins 1 and 3 are the crystal pair), 40.000 MHz fundamental, 9 pF load capacitance. |
| 2 | GND | power_in | Ground pad per the pin connect table (pins 2 and 4 are GND). |
| 3 | XTAL2 | passive | Crystal terminal connected to the quartz blank (pins 1 and 3 are the crystal pair), 40.000 MHz fundamental, 9 pF load capacitance. |
| 4 | GND | power_in | Ground pad per the pin connect table (pins 2 and 4 are GND). |

## Key specifications

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

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Frequency Tolerance |  | -10 |  | 10 | ppm | At 25℃±3℃ | 4 |
| Equivalent Series Resistance | ESR |  |  | 40 | Ω |  | 4 |
| Drive Level | DL |  |  | 100 | μW |  | 4 |
| Frequency Stability | TC | -30 |  | 30 | ppm | Over Operating Temp.Range(Ref.to 25℃) | 4 |
| Operating Temperature |  | -40 |  | 85 | ℃ |  | 4 |
| Storage Temperature |  | -40 |  | 85 | ℃ |  | 4 |
| Aging |  | -3 |  | 3 | ppm | Per Year | 4 |
| Insulation Resistance |  | 500 |  |  | MΩ | At DC 100V | 4 |
| Shunt Capacitance | C0 |  |  | 3 | pF |  | 4 |
| Nominal Frequency | F0 |  | 40 |  | MHz | Fundamental | 4 |
| Load Capacitance | CL |  | 9 |  | pF |  | 4 |

## CAD (KiCad official)

- Symbol: `SX25Y040000B91T001`
- Footprint: `Crystal:Crystal_SMD_2520-4Pin_2.5x2.0mm`
- 3D model: SMD2520-4P (KiCad packages3D, STEP)
- 3D model files: `sx25y040000b91t001-etched.step` / `sx25y040000b91t001-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `sx25y040000b91t001.step` / `sx25y040000b91t001.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [TKD datasheet](docs/sx25y040000b91t001-datasheet.pdf) (13 pp, sha256 `06d85c7c5f47209c`, retrieved 2026-10-22, tier: lcsc)
- **Datasheet language:** Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+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/sx25y040000b91t001-datasheet.pdf)