# MMBZ5252B

**Changjing** · Zener Diodes · SOT-23

MMBZ5252B from Changjing, 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; the symbol on page 1 shows the diode arrow pointing from pin 1 toward pin 3. |
| 2 | NC | unconnected | Not connected internally; the page 1 symbol shows pin 2 as an isolated terminal with no diode connection. |
| 3 | K | passive | Cathode of the zener diode; the zener voltage VZ of 22.8 V min, 24 V nominal and 25.2 V max for the MMBZ5252B is specified at IZT = 5.2 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| 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 | 22.8 | 24 | 25.2 | V | IZT = 5.2 mA | 2 |
| Maximum Zener Impedance | ZZT |  |  | 33 | Ω | @ IZT = 5.2 mA, f = 1kHz | 2 |
| Maximum Zener Impedance (knee) | ZZK |  |  | 600 | Ω | IZK = 0.25mA | 2 |
| Maximum Reverse Leakage Current | IR |  |  | 0.1 | µA | VR = 18 V | 2 |
| Forward Voltage | VF |  |  | 0.9 | V | IF = 10mA | 1 |
| Power Dissipation | PD |  |  | 300 | mW | Ta = 25℃ | 1 |
| Thermal Resistance Junction to Ambient | RθJA |  |  | 417 | ℃/W |  | 1 |
| Junction Temperature | Tj |  |  | 150 | ℃ |  | 1 |
| Storage Temperature Range | Tstg | -55 |  | 150 | ℃ |  | 1 |
| Test Current | IZT |  | 5.2 |  | mA | Ta = 25℃ | 2 |

## CAD (KiCad official)

- Symbol: `MMBZ5252B`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `mmbz5252b-etched.step` / `mmbz5252b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mmbz5252b.step` / `mmbz5252b.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Changjing datasheet](docs/mmbz5252b-datasheet.pdf) (5 pp, sha256 `aaf766a75da5fd05`, retrieved 2026-10-23, 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/mmbz5252b-datasheet.pdf)