# FCS520

**GUOXIN JIAPIN SEMICONDUCTOR** · Bipolar (BJT) · SOT-323

FCS520 from GUOXIN JIAPIN SEMICONDUCTOR, in a SOT-323. 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 | B | input | Base of the FCS520 NPN transistor; the datasheet gives emitter-base breakdown VEBO of 2 V max and VEB=1 V as the test condition for IEBO (0.1 µA max). |
| 2 | E | passive | Emitter of the FCS520 NPN transistor; the emitter-base breakdown voltage VEBO is rated at 2 V. |
| 3 | C | passive | Collector of the FCS520 NPN transistor; collector-emitter breakdown VCEO is rated at 12 V, collector current IC at 100 mA, and power dissipation PC at 150 mW. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | GUOXIN JIAPIN SEMICONDUCTOR |
| Package | SOT-323 |
| Category | Transistors/Thyristors |
| Pins | 3 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Collector-base breakdown voltage (absolute maximum) | VCBO |  |  | 20 | V | TA=25℃ | 1 |
| Collector-emitter breakdown voltage (absolute maximum) | VCEO |  |  | 12 | V | TA=25℃ | 1 |
| Emitter-base breakdown voltage (absolute maximum) | VEBO |  |  | 2 | V | TA=25℃ | 1 |
| Collector current | IC |  |  | 100 | mA | TA=25℃ | 1 |
| Power dissipation | PC |  |  | 150 | mW | TA=25℃ | 1 |
| Junction temperature | Tj |  |  | 150 | ℃ | TA=25℃ | 1 |
| Storage temperature | Tstg | -65 |  | 150 | ℃ | TA=25℃ | 1 |
| Collector-base breakdown voltage | VCBO | 20 |  |  | V | IC=1.0µA | 2 |
| Collector-base leakage current | ICBO |  |  | 0.1 | µA | VCB=10V | 2 |
| Emitter-base leakage current | IEBO |  |  | 0.1 | µA | VEB=1V | 2 |
| DC current gain | hFE | 90 | 150 | 250 |  | VCE=6V，IC=20mA | 2 |
| Noise figure | NF |  | 1.5 | 2 | dB | VCE=6V,IC=5mA,f=1GHz | 2 |
| Output feedback capacitance | Cre |  | 0.4 | 0.7 | pF | VCB=6V,IE=0mA,f=1MHz | 2 |
| Transition frequency | fT |  | 8 |  | GHz | VCE=6V,IC=20mA,f=1GHz | 2 |
| Power gain | /S21e/2 |  | 12.5 |  | dB | VCE=6V,IC=20mA,f=1GHz | 2 |

## CAD (KiCad official)

- Symbol: `FCS520`
- Footprint: `Package_TO_SOT_SMD:SOT-323_SC-70`
- 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files: `fcs520-etched.step` / `fcs520-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `fcs520.step` / `fcs520.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [GUOXIN JIAPIN SEMICONDUCTOR datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590233357650472960) (5 pp, sha256 `c223fa9bce5f26de`, retrieved 2026-10-18, 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:** 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/fcs520-datasheet.pdf)