# 7U28636AE18UCG

**SJK(SHENZHEN CRYSTAL TECH)** · Crystals · SMD3225-4P

7U28636AE18UCG from SJK(SHENZHEN CRYSTAL TECH), in a SMD3225-4P. 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 (28.636360MHz, CL 18pF, ESR 40Ω max), interchangeable with pin 3; pin 1 is the chamfered pad. |
| 2 | GND | power_in | Marked GND in the top-view crystal connection drawing; connect to ground. |
| 3 | XTAL2 | passive | Crystal terminal (28.636360MHz, CL 18pF, ESR 40Ω max), interchangeable with pin 1. |
| 4 | GND | power_in | Marked GND in the top-view crystal connection drawing; connect to ground. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | SJK(SHENZHEN CRYSTAL TECH) |
| Package | SMD3225-4P |
| 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°C | 2 |
| Frequency stability over operating temperature |  | -10 |  | 10 | ppm | -20 °C to +70 °C | 2 |
| Frequency stability over operating temperature |  | -30 |  | 30 | ppm | -40 °C to +85 °C | 2 |
| Aging, first year |  | -3 |  | 3 | ppm/year | @25°C 1st year (Max) | 2 |
| Equivalent series resistance | ESR |  |  | 40 | Ω |  | 2 |
| Shunt capacitance | C0 |  |  | 3 | PF |  | 2 |
| Operating temperature range |  | -40 |  | 85 | °C |  | 2 |
| Storage temperature range |  | -40 |  | 125 | °C |  | 2 |
| Frequency change after reliability tests |  | -5 |  | 5 | ppm | before/after drop, vibration, thermal shock, reflow, high/low temperature tests (section 6) | 4 |
| Resistance (ESR) change after reliability tests |  | -15 |  | 15 | % | before/after drop, vibration, thermal shock, reflow, high/low temperature tests (section 6) | 4 |
| Output frequency (nominal) |  |  | 28.6364 |  | MHz |  | 2 |
| Load capacitance | CL |  | 18 |  | PF |  | 2 |
| Driver level |  |  | 10 |  | µW |  | 2 |

## CAD (KiCad official)

- Symbol: `7U28636AE18UCG`
- Footprint: `Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm`
- 3D model: SMD3225-4P (KiCad packages3D, STEP)
- 3D model files: `7u28636ae18ucg-etched.step` / `7u28636ae18ucg-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `7u28636ae18ucg.step` / `7u28636ae18ucg.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [SJK(SHENZHEN CRYSTAL TECH) datasheet](docs/7u28636ae18ucg-datasheet.pdf) (4 pp, sha256 `05e0d8cfaafdf2a0`, 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/7u28636ae18ucg-datasheet.pdf)