# SMCJ40A-L

**Shandong Jingdao Microelectronics** · ESD And Surge Protection (TVS/ESD) · SMC

SMCJ40A-L from Shandong Jingdao Microelectronics, in a 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 | Cathode | passive | Cathode terminal of the unidirectional SMCJ40A-L TVS diode, with a stand-off reverse voltage (VRWM) of 40 V per the characteristics table. |
| 2 | Anode | passive | Anode terminal of the unidirectional SMCJ40A-L TVS diode, which the datasheet pinning table lists as pin 2 with no additional electrical limits stated. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Shandong Jingdao Microelectronics |
| Package | SMC |
| Category | Circuit Protection |
| 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 | 44.4 |  |  | V | IT = 1 mA | 2 |
| Breakdown voltage (max) | VBR |  |  | 49.1 | V | IT = 1 mA | 2 |
| Maximum clamping voltage | VC |  |  | 64.5 | V | at IPP = 9.3 A | 2 |
| Maximum reverse leakage current | IR |  |  | 1 | µA | at VRWM | 2 |
| Peak pulse current | IPP |  |  | 9.3 | A |  | 2 |
| Maximum instantaneous forward voltage | VF |  |  | 3.5 | V | at 100 A, unidirectional only | 1 |
| Peak pulse power dissipation | PPPM |  |  | 600 | W | 10/1000 µs waveform | 1 |
| Peak forward surge current | IFSM |  |  | 100 | A | 8.3 ms single half sine-wave, superimposed on rated load (JEDEC method) | 1 |
| Operating junction and storage temperature range | Tj, Tstg | -55 |  | 150 | °C |  | 1 |
| Typical thermal resistance, junction to ambient | RθJA |  | 75 |  | °C/W | Note 1 | 1 |
| Thermal resistance, junction to lead | RθJL |  | 15 |  | °C/W |  | 1 |
| Reverse stand-off voltage | VRWM |  | 40 |  | V |  | 2 |

## CAD (KiCad official)

- Symbol: `SMCJ40A-L`
- Footprint: `Diode_SMD:D_SMC`
- 3D model: SMC (KiCad packages3D, STEP)
- 3D model files: `smcj40a-l-etched.step` / `smcj40a-l-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `smcj40a-l.step` / `smcj40a-l.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Shandong Jingdao Microelectronics datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603075794847744000) (4 pp, sha256 `fe884aa643fb34c4`, retrieved 2026-10-16, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-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/smcj40a-l-datasheet.pdf)