# 1.5KE550A

**Littelfuse** · ESD And Surge Protection (TVS/ESD) · DO-201

1.5KE550A from Littelfuse, in a DO-201. 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 | K | passive | Cathode, the lead on the colour-band end of the uni-directional 1.5KE550A; it goes positive relative to the anode in normal standoff operation (VR 468 V, VBR 522.5-577.5 V at 1 mA, VC 760 V at 2.7 A). |
| 2 | A | passive | Anode, the lead opposite the cathode band of the uni-directional 1.5KE550A; it conducts forward with VF below 5.0 V at 100 A (stacked-die part) and is rated 1500 W peak pulse power at 10/1000 µs. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Littelfuse |
| Package | DO-201 |
| Category | Circuit Protection |
| Pins | 2 |

## CAD (KiCad official)

- Symbol: `1.5KE550A`
- Footprint: `Diode_THT:D_DO-201AD_P15.24mm_Horizontal`
- 3D model: DO-201 (KiCad packages3D, STEP)

## Provenance

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

- **Datasheet:** [Littelfuse datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8589788497042173952) (6 pp, sha256 `4290e23a327d9203`, retrieved 2026-10-13, 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/1-5ke550a-datasheet.pdf)