# 8121S-40.000MQ33DTL

**HCI** · Temperature Compensated Crystal Oscillators (TCXO) · SMD2016-4P

8121S-40.000MQ33DTL from HCI, in a SMD2016-4P. 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 | GND/NC | passive | Ground or N.C. per the pad function table; the datasheet gives no further limits. |
| 2 | GND | power_in | Ground pin; the metal lid is connected to ground pin 2. |
| 3 | RF | output | Clipped sine wave RF output, 0.8Vp-p minimum into a 10kΩ/10pF load. |
| 4 | Vcc | power_in | Supply voltage pin for 1.8V, 2.5V, 2.8V, 3.0V or 3.3V versions. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | HCI |
| Package | SMD2016-4P |
| 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 range |  | 10 |  | 52 | MHz |  | 1 |
| Frequency tolerance (initial) |  | -1 |  | 1 | ppm | Initial tol. @+25°C | 1 |
| Aging per year |  | -1 |  | 1 | ppm | per year @+25°C | 1 |
| Output voltage level |  | 0.8 |  |  | Vp-p |  | 1 |
| Phase jitter RMS |  |  |  | 1 | ps | 12kHz≤Fj≤20MHz | 1 |
| Supply current |  |  |  | 1.5 | mA | @10kΩ/10pF | 1 |
| Supply current (higher value) |  |  |  | 2 | mA | @10kΩ/10pF (higher value >26MHz) | 1 |

## CAD (KiCad official)

- Symbol: `8121S-40.000MQ33DTL`
- Footprint: `Crystal:Crystal_SMD_2016-4Pin_2.0x1.6mm`
- 3D model: SMD2016-4P (KiCad packages3D, STEP)
- 3D model files: `8121s-40-000mq33dtl-etched.step` / `8121s-40-000mq33dtl-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `8121s-40-000mq33dtl.step` / `8121s-40-000mq33dtl.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [HCI datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603369298333757440) (1 pp, sha256 `f15e57437578c64d`, 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/8121s-40-000mq33dtl-datasheet.pdf)