# ECS-250-8-36B2-CKM-TR

**ECS** · Crystals · SMD2520-4P

ECS-250-8-36B2-CKM-TR from ECS, 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 | In/Out | passive | Crystal terminal labeled In/Out in the Pad Connections table; pads 1 and 3 are interchangeable because the crystal is symmetrical. |
| 2 | Gnd | power_in | Ground pad, listed as Gnd in the Pad Connections table; the datasheet gives no further electrical limit for this pad. |
| 3 | Out/In | passive | Crystal terminal labeled Out/In in the Pad Connections table; pads 1 and 3 are interchangeable because the crystal is symmetrical. |
| 4 | Gnd | power_in | Ground pad, listed as Gnd in the Pad Connections table; the datasheet gives no further electrical limit for this pad. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ECS |
| 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 @ +25°C (C option) |  | -10 |  | 10 | ppm | @ +25°C, C option (P/N tolerance code C = ±10 ppm) | 1 |
| Frequency stability (K option) |  | -10 |  | 10 | ppm | K option (P/N stability code K = ±10 ppm); table row prints (KY option) -30 ~ +85°C | 1 |
| Aging (first year) |  | -2 |  | 2 | ppm | First year @ +25°C ±3°C | 1 |
| Equivalent series resistance (ESR) | ESR |  |  | 50 | Ω | Frequency 20.000 ~ 29.999 MHz (25 MHz part) | 1 |
| Operating temperature (M option) | Topr | -20 |  | 70 | °C | M option per P/N guide (-20 ~ +70°C) | 1 |
| Storage temperature | Tstg | -55 |  | 125 | °C |  | 1 |
| Peak solder temperature |  |  |  | 260 | °C | Max 10 sec, 2 cycles max | 2 |
| Nominal frequency | f |  | 25 |  | MHz | P/N code 250 = 25.000 MHz | 1 |
| Load capacitance | CL |  | 8 |  | pF | P/N load code 8 = 8 pF | 1 |
| Shunt capacitance | Co |  | 3 |  | pF |  | 1 |
| Drive level | DL |  |  | 100 | μW |  | 1 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts |  | gold | MSL 1, Lead Finish Au POCKET TAPE DIMENSIONS (mm) | 2 |

## CAD (KiCad official)

- Symbol: `ECS-250-8-36B2-CKM-TR`
- Footprint: `Crystal:Crystal_SMD_2520-4Pin_2.5x2.0mm`
- 3D model: SMD2520-4P (KiCad packages3D, STEP)
- 3D model files: `ecs-250-8-36b2-ckm-tr-etched.step` / `ecs-250-8-36b2-ckm-tr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ecs-250-8-36b2-ckm-tr.step` / `ecs-250-8-36b2-ckm-tr.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [ECS datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590909354952368128) (2 pp, sha256 `de0ae185b029dac4`, retrieved 2026-10-16, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (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/ecs-250-8-36b2-ckm-tr-datasheet.pdf)