# 5.0SMDJ300A

**Zhengxin(正芯)** · IC · DO-214AB(SMC)

5.0SMDJ300A from Zhengxin(正芯), in a DO-214AB(SMC). 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 | K | passive | Cathode terminal of the unidirectional TVS, marked by the band on the package, connected to the protected line (VRWM 300 V, VBR 335-371 V at 1.0 mA, max clamping 486 V at 10.3 A). |
| 2 | A | passive | Anode terminal of the unidirectional TVS, at the end opposite the cathode band, usually connected to ground (5000 W peak pulse power at 10/1000 μs). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Zhengxin(正芯) |
| Package | DO-214AB(SMC) |
| Category |  |
| Pins | 2 |

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Breakdown voltage (min) | VBR | 335 |  |  | V | @ IT = 1.0 mA | 3 |
| Breakdown voltage (max) | VBR |  |  | 371 | V | @ IT = 1.0 mA | 3 |
| Maximum reverse leakage current | IR |  |  | 5 | μA | @ VRWM = 300 V | 3 |
| Maximum reverse surge current | IPP |  |  | 10.3 | A |  | 3 |
| Maximum clamping voltage | VC |  |  | 486 | V | @ IPP | 3 |
| Maximum instantaneous forward voltage | VFM |  |  | 5 | V | at 100 A, unidirectional only; 5.0 V max for devices with VBR > 85 V | 1 |
| Peak power dissipation | PPPM |  |  | 5000 | W | 10/1000 μs waveform | 1 |
| Power dissipation on infinite heat sink | PD |  |  | 6.5 | W | on infinite heat sink at TL = 75 ℃ | 1 |
| Peak forward surge current | IFSM |  |  | 300 | A | 8.3 ms single half sine-wave, unidirectional only | 1 |
| Operating junction and storage temperature range | TJ,TSTG | -55 |  | 150 | ℃ |  | 1 |
| Thermal resistance, junction to ambient | RθJ-A |  | 75 |  | ℃/W | junction to ambient | 2 |
| Thermal resistance, junction to lead | RθJ-L |  | 15 |  | ℃/W | junction to lead | 2 |
| Thermal resistance, junction to case | RθJ-C |  | 13 |  | ℃/W | junction to case | 2 |

## 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 |  | tin | ● Terminals: Tin plated leads, solderable per J-STD￾002 and JESD22-B102 ● Polarity: For uni-directional types the band denotes | 1 |

## CAD (KiCad official)

- Symbol: `5.0SMDJ300A`
- Footprint: `Diode_SMD:D_SMC`
- 3D model: DO-214AB(SMC) (KiCad packages3D, STEP)
- 3D model files: `5-0smdj300a-etched.step` / `5-0smdj300a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `5-0smdj300a.step` / `5-0smdj300a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Zhengxin(正芯) datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8602994596234883072) (5 pp, sha256 `b6677432328dd8c0`, retrieved 2026-10-18, 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/5-0smdj300a-datasheet.pdf)