# JSMD0805-300L

**Shenzhen Jinkaisheng Elec** · Resettable Fuses · 0805

JSMD0805-300L from Shenzhen Jinkaisheng Elec, 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 | Terminal 1 of the non-polarized PTC device (JSMD0805-300L: Vmax 6.0 V dc, Imax 50 A, Ihold 3.0 A, Itrip 6.0 A at 25°C), interchangeable with terminal 2. |
| 2 | 2 | passive | Terminal 2 of the non-polarized PTC device (JSMD0805-300L: Vmax 6.0 V dc, Imax 50 A, Ihold 3.0 A, Itrip 6.0 A at 25°C), interchangeable with terminal 1. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Shenzhen Jinkaisheng Elec |
| Package | 0805 |
| 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 |
|---|---|---|---|---|---|---|---|
| Minimum device resistance prior to tripping | Ri min | 0.004 |  |  | Ω | 25°C, prior to tripping | 1 |
| Maximum device resistance one hour post reflow | R1max |  |  | 0.03 | Ω | Measured one hour post reflow | 1 |
| Maximum operating voltage | Vmax |  |  | 6 | V dc | Maximum operating voltage device can withstand without damage at rated current (Imax) | 1 |
| Maximum fault current | Imax |  |  | 50 | A | Maximum fault current device can withstand without damage at rated voltage (Vmax) | 1 |
| Hold current | I hold |  |  | 3 | A | 25°C still air; maximum current device will not trip | 1 |
| Trip current | I trip | 6 |  |  | A | 25°C still air; minimum current at which device will always trip | 1 |
| Maximum time to trip |  |  |  | 5 | s | At 8.0 A current | 1 |
| Passive aging resistance change |  | -5 |  | 5 | % | Passive aging +85°C, 1000 hrs; typical | 1 |
| Humidity aging resistance change |  | -5 |  | 5 | % | Humidity aging +85°C, 85% R.H., 168 hours; typical | 1 |
| Thermal shock resistance change |  | -33 |  | 33 | % | Thermal shock +85°C to -40°C, 20 times; typical | 1 |
| Recommended hold current at ambient -40°C |  |  |  | 4.29 | A | Thermal derating chart, ambient -40°C | 2 |
| Recommended hold current at ambient -20°C |  |  |  | 3.75 | A | Thermal derating chart, ambient -20°C | 2 |
| Recommended hold current at ambient 0°C |  |  |  | 3.53 | A | Thermal derating chart, ambient 0°C | 2 |
| Recommended hold current at ambient 25°C |  |  |  | 3 | A | Thermal derating chart, ambient 25°C | 2 |
| Recommended hold current at ambient 40°C |  |  |  | 2.65 | A | Thermal derating chart, ambient 40°C | 2 |
| Recommended hold current at ambient 50°C |  |  |  | 2.5 | A | Thermal derating chart, ambient 50°C | 2 |
| Recommended hold current at ambient 60°C |  |  |  | 2.4 | A | Thermal derating chart, ambient 60°C | 2 |
| Recommended hold current at ambient 70°C |  |  |  | 1.94 | A | Thermal derating chart, ambient 70°C | 2 |
| Recommended hold current at ambient 85°C |  |  |  | 1.36 | A | Thermal derating chart, ambient 85°C | 2 |
| Ambient operating temperature |  | -40 |  | 85 | °C | Ambient operating conditions | 2 |
| Maximum surface temperature in tripped state |  |  |  | 125 | °C | Device in the tripped state | 2 |
| Power dissipation in tripped state | Pd |  | 1.2 |  | W | Tripped state, 25°C still air, at rated voltage | 1 |
| Storage temperature |  | 0 |  | 35 | °C | Storage, ≤70% RH | 3 |
| Peak reflow temperature | Tp |  |  | 260 | °C | Pb-free reflow profile | 3 |
| Average ramp-up rate (Ts max to Tp) |  |  |  | 3 | °C/second | Pb-free reflow profile | 3 |
| Ramp-down rate |  |  |  | 6 | °C/second | Pb-free reflow profile | 3 |
| Time 25°C to peak temperature |  |  |  | 8 | minutes | Pb-free reflow profile | 3 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts | Copper | tin | Terminal pad materials：Tin-plated Nickel-Copper | 4 |

## CAD (KiCad official)

- Symbol: `JSMD0805-300L`
- Footprint: `Fuse:Fuse_0805_2012Metric`
- 3D model: 0805 (KiCad packages3D, STEP)
- 3D model files: `jsmd0805-300l-etched.step` / `jsmd0805-300l-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `jsmd0805-300l.step` / `jsmd0805-300l.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Shenzhen Jinkaisheng Elec datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590226442270105600) (7 pp, sha256 `ac0966d3ccc20817`, retrieved 2026-10-19, 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/jsmd0805-300l-datasheet.pdf)