# ECS-250-20-33-CKM-TR3

**ECS** · Crystals · SMD3225-4P

ECS-250-20-33-CKM-TR3 from ECS, 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 | In/Out | passive | Crystal terminal (In/Out) per the pad connection table; pads 1 and 3 are interchangeable because the crystal is symmetrical, and the bottom chamfer on pad 4 or pad 1 has no electrical significance. |
| 2 | Gnd | power_in | Ground pad per the pad connection table; the datasheet states no further electrical limits for this pin. |
| 3 | Out/In | passive | Crystal terminal (Out/In) per the pad connection table; pad 3 is interchangeable with pad 1 because the crystal is symmetrical. |
| 4 | Gnd | power_in | Ground pad per the pad connection table; the datasheet states no further electrical limits for this pin, and the bottom chamfer may be located on this pad with no electrical significance. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ECS |
| Package | SMD3225-4P |
| 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 (decoded from P/N tolerance code C = ±10 ppm) |  | -10 |  | 10 | ppm | @ +25°C | 1 |
| Frequency stability (decoded from P/N stability code K = ±10 ppm; temp code M) |  | -10 |  | 10 | ppm | -20 ~ +70°C | 1 |
| Aging (first year) |  | -5 |  | 5 | ppm | @ +25°C ±3°C | 1 |
| Frequency range |  | 8 |  | 54 | MHz |  | 1 |
| Shunt Capacitance | Co |  |  | 5 | pF |  | 1 |
| Drive Level | DL |  |  | 100 | μW |  | 1 |
| Equivalent Series Resistance (ESR) | ESR |  |  | 40 | Ω | 24.000 ~ 54.000 MHz | 1 |
| Operating Temperature | Topr | -20 |  | 70 | °C |  | 1 |
| Storage Temperature | Tstg | -55 |  | 125 | °C |  | 1 |
| Nominal frequency (decoded from P/N code 250) |  |  | 25 |  | MHz | P/N code 250 | 2 |
| Load Capacitance (from P/N code 20) | CL |  | 20 |  | pF | Specify in P/N | 1 |

## CAD (KiCad official)

- Symbol: `ECS-250-20-33-CKM-TR3`
- Footprint: `Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm`
- 3D model: SMD3225-4P (KiCad packages3D, STEP)
- 3D model files: `ecs-250-20-33-ckm-tr3-etched.step` / `ecs-250-20-33-ckm-tr3-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ecs-250-20-33-ckm-tr3.step` / `ecs-250-20-33-ckm-tr3.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/8590909031186194432) (2 pp, sha256 `7f56a768dd3d4594`, retrieved 2026-10-15, 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-250-20-33-ckm-tr3-datasheet.pdf)