# CJ15-120001210B20

**Changjing** · Crystals · SMD2520-4P

CJ15-120001210B20 from Changjing, 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 (chamfered pad) connected to one side of the 12MHz resonator in the bottom-view schematic; the unit is 12pF load, fundamental mode. |
| 2 | NC | unconnected | Pad shown with no connection to the resonator in the bottom-view drawing; used for mechanical mounting. |
| 3 | XTAL2 | passive | Crystal terminal connected to the other side of the 12MHz resonator in the bottom-view schematic; the unit is 12pF load, fundamental mode. |
| 4 | NC | unconnected | Pad shown with no connection to the resonator in the bottom-view drawing; used for mechanical mounting. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SMD2520-4P |
| Category | Crystals, Oscillators, Resonators |
| 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 | △f/f | -10 |  | 10 | ppm |  | 2 |
| Frequency Temperature Stability |  | -20 |  | 20 | ppm |  | 2 |
| Aging | △fA | -3 |  | 3 | ppm per Year |  | 2 |
| Resonance Resistance |  |  |  | 150 | ohms |  | 2 |
| Shunt Capacitance | C0 |  |  | 2 | pF |  | 2 |
| Drive Level | DL |  |  | 100 | μW |  | 2 |
| Operating Temperature Range | TOPR | -40 |  | 85 | °C |  | 2 |
| Storage Temperature Range | TSTG | -55 |  | 125 | °C |  | 2 |
| Insulation Resistance | IR | 500 |  |  | M ohms |  | 2 |
| Nominal Frequency | f |  | 12 |  | MHz |  | 2 |
| Load Capacitance | CL |  | 12 |  | pF |  | 2 |

## CAD (KiCad official)

- Symbol: `CJ15-120001210B20`
- Footprint: `Crystal:Crystal_SMD_2520-4Pin_2.5x2.0mm`
- 3D model: SMD2520-4P (KiCad packages3D, STEP)
- 3D model files: `cj15-120001210b20-etched.step` / `cj15-120001210b20-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `cj15-120001210b20.step` / `cj15-120001210b20.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Changjing datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8589952019885817856) (8 pp, sha256 `c4eeee1b4eb210c0`, retrieved 2026-10-21, tier: lcsc)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/cj15-120001210b20-datasheet.pdf)