# SRDA05-4

**TECH PUBLIC** · ESD And Surge Protection (TVS/ESD) · SOP-8

SRDA05-4 from TECH PUBLIC, in a SOP-8. 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 | I/O 1 | passive | Protected I/O line 1, steered by the diode array to REF 1/REF 2; junction capacitance to ground 20pF max. |
| 2 | REF 1 | passive | Reference pin 1 (positive reference rail of the diode array), tied internally to pin 3. |
| 3 | REF 1 | passive | Reference pin 1 (positive reference rail of the diode array), tied internally to pin 2. |
| 4 | I/O 2 | passive | Protected I/O line 2, steered by the diode array to REF 1/REF 2; junction capacitance to ground 20pF max. |
| 5 | REF 2 | passive | Reference pin 2 (ground-side reference rail of the diode array), tied internally to pin 8. |
| 6 | I/O 3 | passive | Protected I/O line 3, steered by the diode array to REF 1/REF 2; junction capacitance to ground 20pF max. |
| 7 | I/O 4 | passive | Protected I/O line 4, steered by the diode array to REF 1/REF 2; junction capacitance to ground 20pF max. |
| 8 | REF 2 | passive | Reference pin 2 (ground-side reference rail of the diode array), tied internally to pin 5. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | TECH PUBLIC |
| Package | SOP-8 |
| Category | Circuit Protection |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `SRDA05-4`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `srda05-4-etched.step` / `srda05-4-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `srda05-4.step` / `srda05-4.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [TECH PUBLIC datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590233505788420096) (4 pp, sha256 `17e838d45ca253b1`, retrieved 2026-10-19, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (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/srda05-4-datasheet.pdf)