# 1SMA4749A

**MDD Microdiode Semiconductor** · Zener Diodes · SMA(DO-214AC)

1SMA4749A from MDD Microdiode Semiconductor, in a SMA(DO-214AC). 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, marked by the polarity band on the body, which goes positive in Zener (reverse) breakdown regulation; the datasheet gives power dissipation of 1.0 W at TA=50°C and a 1.2 V forward voltage. |
| 2 | A | passive | Anode terminal, the end without the polarity band; the datasheet gives a peak forward surge current of 10.0 A (8.3 ms half sine-wave) and an operating and storage range of -55 to +150 °C. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | MDD Microdiode Semiconductor |
| Package | SMA(DO-214AC) |
| Category | Diodes |
| Pins | 2 |

## CAD (KiCad official)

- Symbol: `1SMA4749A`
- Footprint: `Diode_SMD:D_SMA`
- 3D model: SMA(DO-214AC) (KiCad packages3D, STEP)
- 3D model files: `1sma4749a-etched.step` / `1sma4749a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `1sma4749a.step` / `1sma4749a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [MDD Microdiode Semiconductor datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588880494486294528) (5 pp, sha256 `b0a657aa72d39a2a`, retrieved 2026-10-12, 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/1sma4749a-datasheet.pdf)