# ECS-120-20-33-CKM-TR

**ECS** · Crystals · SMD3225-4P

ECS-120-20-33-CKM-TR 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 labelled In/Out; the datasheet states pads 1 and 3 are interchangeable and the bottom chamfer has no electrical significance. |
| 2 | Gnd | power_in | Ground pad connected to the crystal case, as printed in the pad connections table. |
| 3 | Out/In | passive | Crystal terminal labelled Out/In; the datasheet states pads 1 and 3 are interchangeable and have no fixed polarity. |
| 4 | Gnd | power_in | Ground pad; the datasheet notes the chamfer on the bottom can be on pad 4 or pad 1 with no electrical significance. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ECS |
| Package | SMD3225-4P |
| Category | Resonators/Oscillators |
| 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 | @ +25°C | 1 |
| Frequency Stability |  | -10 |  | 10 | ppm | -20 ~ +70°C | 1 |
| Aging (First Year) |  | -5 |  | 5 | ppm | First year @ +25°C ±3°C | 1 |
| Operating Temperature | Topr | -20 |  | 70 | °C |  | 1 |
| Storage Temperature | Tstg | -55 |  | 125 | °C |  | 1 |
| Shunt Capacitance | Co |  |  | 5 | pF |  | 1 |
| Equivalent Series Resistance | ESR |  |  | 100 | Ω | 10.000 ~ 15.999 MHz | 1 |
| Drive Level | DL |  |  | 100 | μW |  | 1 |
| Frequency |  |  | 12 |  | MHz | P/N code 120 = 12.000 MHz | 2 |
| Load Capacitance |  |  | 20 |  | pF | Specify in P/N (code 20 = 20 pF) | 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-120-20-33-CKM-TR`
- Footprint: `Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm`
- 3D model: SMD3225-4P (KiCad packages3D, STEP)
- 3D model files: `ecs-120-20-33-ckm-tr-etched.step` / `ecs-120-20-33-ckm-tr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ecs-120-20-33-ckm-tr.step` / `ecs-120-20-33-ckm-tr.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [ECS datasheet](docs/ecs-120-20-33-ckm-tr-datasheet.pdf) (2 pp, sha256 `7f56a768dd3d4594`, retrieved 2026-10-28, 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-120-20-33-ckm-tr-datasheet.pdf)