# BLM21BD331SN1D

**Murata Electronics** · Ferrite Beads · 0805

BLM21BD331SN1D from Murata Electronics, in a 0805. 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 | 1 | passive | First electrode of the two-terminal ferrite bead (330 ohm typ. at 100MHz, rated 300 mA, 0.3 ohm max. DC resistance initial); terminals are interchangeable. |
| 2 | 2 | passive | Second electrode of the two-terminal ferrite bead, in series with the first through the inductor-plus-resistance equivalent circuit; operating range -55°C to +125°C. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Murata Electronics |
| Package | 0805 |
| Category | Filters |
| 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 |
|---|---|---|---|---|---|---|---|
| DC resistance |  |  | 0.3 | 0.4 | Ω | Initial values; measured with digital multimeter, excludes substrate and wire resistance | 2 |
| Impedance tolerance at 100MHz |  | -25 |  | 25 | % | at 100MHz±1MHz | 2 |
| Impedance at 100MHz |  |  | 330 |  | Ω | at 100MHz±1MHz | 2 |
| Rated current |  |  |  | 300 | mA |  | 2 |
| Operating temperature |  | -55 |  | 125 | °C |  | 3 |
| Storage temperature |  | -55 |  | 125 | °C |  | 3 |
| Impedance change after resistance to soldering heat |  | -30 |  | 30 | % | At 100MHz after soldering heat test (Sn-3.0Ag-0.5Cu, 270°C±5°C, 10s±0.5s); BLM21SN type is ±50%, not this part | 4 |

## CAD (KiCad official)

- Symbol: `BLM21BD331SN1D`
- Footprint: `Inductor_SMD:L_0805_2012Metric`
- 3D model: 0805 (KiCad packages3D, STEP)
- 3D model files: `blm21bd331sn1d-etched.step` / `blm21bd331sn1d-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `blm21bd331sn1d.step` / `blm21bd331sn1d.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Murata Electronics datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8589887302232412160) (10 pp, sha256 `778f317c7d9e698b`, retrieved 2026-11-07, 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/blm21bd331sn1d-datasheet.pdf)