# BSMD1210L-350

**BHFUSE** · Resettable Fuses · 1210

BSMD1210L-350 from BHFUSE, in a 1210. 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 | One terminal pad of the non-polarized PTC device (pad 1.00±0.1 x 2.70±0.1 mm), rated Ihold 3.50 A, Itrip 7.00 A, Vmax 6.0 Vdc, Imax 50 A. |
| 2 | 2 | passive | Second terminal pad of the non-polarized PTC device, placed 2.00±0.1 mm from the other pad, with Rmin 0.003 Ω and R1max 0.013 Ω. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | BHFUSE |
| Package | 1210 |
| Category | Circuit Protection |
| 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 |
|---|---|---|---|---|---|---|---|
| Hold current (Ihold) | Ihold |  |  | 3.5 | A | 25°C still air | 1 |
| Trip current (Itrip) | Itrip | 7 |  |  | A | 25°C still air | 1 |
| Maximum voltage (Vmax) | Vmax |  |  | 6 | Vdc | at rated current (Imax) | 1 |
| Maximum fault current (Imax) | Imax |  |  | 50 | A | at rated voltage (Vmax) | 1 |
| Minimum initial resistance (Rmin) | Rmin | 0.003 |  |  | Ω | initial (un-soldered) state | 1 |
| Maximum resistance after trip or reflow (R1max) | R1max |  |  | 0.013 | Ω | 25°C, measured one hour after tripping or reflow soldering of 260°C for 20 sec | 1 |
| Typical power dissipated in tripped state (Pd typ) | Pd |  | 1.2 |  | W | tripped state, 25°C still air | 1 |
| Time to trip: current |  |  | 17.5 |  | A | time to trip column; paired with 5.0 s | 1 |
| Time to trip: time |  |  | 5 |  | s | time to trip column; paired with 17.5 A | 1 |
| Ihold vs ambient temperature | Ihold |  |  | 3.57 | A | ambient -40 °C | 3 |
| Ihold vs ambient temperature | Ihold |  |  | 4.29 | A | ambient -20 °C | 3 |
| Ihold vs ambient temperature | Ihold |  |  | 3.88 | A | ambient 0 °C | 3 |
| Ihold vs ambient temperature | Ihold |  |  | 3.5 | A | ambient 25 °C | 3 |
| Ihold vs ambient temperature | Ihold |  |  | 2.98 | A | ambient 40 °C | 3 |
| Ihold vs ambient temperature | Ihold |  |  | 2.68 | A | ambient 50 °C | 3 |
| Ihold vs ambient temperature | Ihold |  |  | 2.34 | A | ambient 60 °C | 3 |
| Ihold vs ambient temperature | Ihold |  |  | 2.03 | A | ambient 70 °C | 3 |
| Ihold vs ambient temperature | Ihold |  |  | 1.66 | A | ambient 85 °C | 3 |
| Ambient operating temperature |  | -40 |  | 85 | °C |  | 3 |
| Maximum surface temperature in tripped state |  |  |  | 125 | °C | device in tripped state | 3 |

## CAD (KiCad official)

- Symbol: `BSMD1210L-350`
- Footprint: `Fuse:Fuse_1210_3225Metric`
- 3D model: 1210 (KiCad packages3D, STEP)
- 3D model files: `bsmd1210l-350-etched.step` / `bsmd1210l-350-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bsmd1210l-350.step` / `bsmd1210l-350.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [BHFUSE datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8618847312538329088) (7 pp, sha256 `16be034a18f85d4c`, retrieved 2026-10-18, 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/bsmd1210l-350-datasheet.pdf)