# BFG540

**Slkor SLKORMICRO Elec** · RF Amplifiers · SOT-143-4

BFG540 from Slkor SLKORMICRO Elec, in a SOT-143-4. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | C | passive | Collector of NPN transistor. Wide collector lead per SOT143B package. Max IC=120mA, BVCEO=15V, BVCBO=20V. |
| 2 | B | passive | Base of NPN transistor. BVEBO=2.5V. Drives high-gain low-noise RF amplifier operation up to fT=9GHz. |
| 3 | E | passive | Emitter of NPN transistor. Shared with pin 4 (dual emitter leads for improved grounding/thermal performance in SOT143B). |
| 4 | E | passive | Second emitter of NPN transistor, tied internally to pin 3. Dual emitter leads reduce parasitic inductance for microwave LNA use. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Slkor SLKORMICRO Elec |
| Package | SOT-143-4 |
| Category | RF And Wireless |
| Pins | 4 |

## Ordering variants

Same part, different packaging or reel option.

- `BFG540`
- `BFG540/X`

## CAD (KiCad official)

- Symbol: `BFG540`
- Footprint: `Package_TO_SOT_SMD:SOT-143`
- 3D model: SOT-143-4 (KiCad packages3D, STEP)
- 3D model files: `bfg540-etched.step` / `bfg540-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bfg540.step` / `bfg540.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Slkor SLKORMICRO Elec datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588917853520715776) (5 pp, sha256 `5b47e88954dfd847`, retrieved 2026-08-17, tier: lcsc)
- **Datasheet language:** Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/bfg540-datasheet.pdf)