# TZ0661C

**TST** · Crystals · SMD2520-4P

TZ0661C from TST, 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 (IN/OUT) for the 26.000000 MHz fundamental-mode crystal unit, load capacitance 9 pF. |
| 2 | GND | power_in | Ground pin of the crystal unit package. |
| 3 | IN/OUT | passive | Second crystal terminal (IN/OUT) for the 26.000000 MHz crystal, drive level 50 uW typical and 100 uW max. |
| 4 | GND | power_in | Ground pin of the crystal unit package. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | TST |
| 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 Stability over Operating Temperature Range |  | -9 |  | 9 | ppm | referred to the value at 25°C | 3 |
| Frequency Make Tolerance (FL) | FL | -10 |  | 10 | ppm | @ 25°C +/- 3°C | 3 |
| Equivalent Series Resistance | ESR |  |  | 60 | Ω |  | 3 |
| Drive Level |  |  | 50 | 100 | uW | Nominal Drive Level | 3 |
| Shunt Capacitance | Co |  |  | 2 | pF |  | 3 |
| Insulation Resistance |  | 500 |  |  | MΩ | DC 100V | 3 |
| Aging |  | -1 |  | 1 | ppm/year |  | 3 |
| Operating Temperature Range |  | -20 |  | 75 | °C |  | 3 |
| Storage Temperature Range |  | -40 |  | 85 | °C |  | 3 |
| Nominal Frequency |  |  | 26 |  | MHz | Fundamental mode | 3 |
| Load Capacitance | CL |  | 9 |  | pF |  | 3 |
| Unit Weight |  | 9 | 9.5 | 10 | mg | 9.5 +/-0.5mg | 3 |

## CAD (KiCad official)

- Symbol: `TZ0661C`
- Footprint: `Crystal:Crystal_SMD_2520-4Pin_2.5x2.0mm`
- 3D model: SMD2520-4P (KiCad packages3D, STEP)
- 3D model files: `tz0661c-etched.step` / `tz0661c-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tz0661c.step` / `tz0661c.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [TST datasheet](docs/tz0661c-datasheet.pdf) (7 pp, sha256 `600a44bf1426c87e`, retrieved 2026-10-22, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-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/tz0661c-datasheet.pdf)