# MMBZ5248B

**EIC Semicon** · Zener Diodes · SOT-23

MMBZ5248B from EIC Semicon, in a SOT-23. 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 | A | passive | Anode of the zener diode, shown connected to the diode symbol in the bottom-view drawing. |
| 2 | NC | unconnected | Not connected internally; the bottom-view drawing shows no connection to the diode symbol. |
| 3 | K | passive | Cathode of the zener diode, shown connected to the bar side of the diode symbol; MMBZ5248B has a nominal zener voltage of 18 V (17.10 V to 18.90 V) at 7.0 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | EIC Semicon |
| Package | SOT-23 |
| Category | Diodes |
| Pins | 3 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Zener voltage | VZ | 17.1 | 18 | 18.9 | V | IZT = 7.0 mA, Ta = 25 °C, pulsed tp = 20 ms | 2 |
| Maximum Zener impedance | ZZT |  |  | 21 | Ω | IZT = 7.0 mA | 2 |
| Maximum Zener impedance | ZZK |  |  | 600 | Ω | IZK = 0.25 mA | 2 |
| Maximum reverse leakage current | IR |  |  | 0.1 | μA | VR = 14 V | 2 |
| Maximum forward voltage | VF |  |  | 0.9 | V | IF = 10 mA | 2 |
| Power dissipation | PD |  |  | 350 | mW | Ta = 25 °C | 1 |
| Junction temperature | TJ |  |  | 150 | °C |  | 1 |
| Storage temperature range | TSTG | -55 |  | 150 | °C |  | 1 |
| Thermal resistance, junction to ambient air | RθJA |  | 357 |  | °C/W | Junction to ambient air | 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 |
|---|---|---|---|---|
| housing | Abs |  | * Case : SOT-23 plastic Case Absolute Maximum Ratings ( Ta = 25 °C ) | 1 |

## CAD (KiCad official)

- Symbol: `MMBZ5248B`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `mmbz5248b-etched.step` / `mmbz5248b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mmbz5248b.step` / `mmbz5248b.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [EIC Semicon datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590227443421515776) (3 pp, sha256 `e80dac09e768e0a4`, retrieved 2026-10-17, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-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/mmbz5248b-datasheet.pdf)