# 1SMA4729A

**hongjiacheng** · Zener Diodes · DO-214AC(SMA)

1SMA4729A from hongjiacheng, in a DO-214AC(SMA). 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 | One of the two terminals of the SMA zener diode shown in the function diagram; for the 1SMA4729A the nominal zener voltage is 3.6 V (3.40 V min to 3.80 V max) at IZT 69 mA, with ZZT 10 Ω and IR 100 µA at VR 1 V. |
| 2 | A | passive | The second terminal of the SMA zener diode shown in the function diagram; the package's cathode end is marked by a cathode line, and the maximum admissible zener current IZM for the 1SMA4729A is 263 mA with 1000 mW power dissipation. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | hongjiacheng |
| Package | DO-214AC(SMA) |
| Category | Diodes |
| 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 |
|---|---|---|---|---|---|---|---|
| Reverse zener voltage | VZ | 3.4 | 3.6 | 3.8 | V | @ IZT = 69 mA | 2 |
| Maximum Zener impedance | ZZT |  |  | 10 | Ω | @ IZT = 69 mA | 2 |
| Power dissipation | PD |  |  | 1000 | mW | Tc=75℃ | 1 |
| Storage temperature | Tstg | -55 |  | 150 | ℃ |  | 1 |
| Junction temperature | Tj | -55 |  | 150 | ℃ |  | 1 |
| Typical thermal resistance, junction to ambient | RθJ-A |  | 250 |  | ℃/W |  | 1 |

## CAD (KiCad official)

- Symbol: `1SMA4729A`
- Footprint: `Diode_SMD:D_SMA`
- 3D model: DO-214AC(SMA) (KiCad packages3D, STEP)
- 3D model files: `1sma4729a-etched.step` / `1sma4729a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `1sma4729a.step` / `1sma4729a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [hongjiacheng datasheet](docs/1sma4729a-datasheet.pdf) (4 pp, sha256 `a029b6256b4d07a8`, retrieved 2026-10-21, 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/1sma4729a-datasheet.pdf)