# SF34 TB

**YFW** · Fast Recovery / High Efficiency Diodes · DO-27

SF34 TB from YFW, in a DO-27. 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, the lead at the end of the body marked with the cathode band; SF34 has VRRM 200 V, VRMS 140 V and VDC 200 V. |
| 2 | A | passive | Anode, the lead at the end of the body opposite the cathode band; average forward current 3.0 A at Tc = 100 °C, peak surge 150.0 A (8.3 ms half sine). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | YFW |
| Package | DO-27 |
| Category | Diodes |
| Pins | 2 |

## CAD (KiCad official)

- Symbol: `SF34 TB`
- Footprint: `Diode_THT:D_DO-27_P15.24mm_Horizontal`
- 3D model: DO-27 (KiCad packages3D, STEP)

## Provenance

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

- **Datasheet:** [YFW datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590927207680458752) (3 pp, sha256 `65f9498afa6a1c36`, retrieved 2026-10-13, 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/sf34-tb-datasheet.pdf)