# SRDA3.3-4DR2G

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

SRDA3.3-4DR2G 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, with 7pF max (5pF typ) junction capacitance to ground and 3pF typ between I/O pins. |
| 2 | REF 1 | power_in | Positive reference (steering-diode top rail, tied to the TVS diode), internally common with pin 3. |
| 3 | REF 1 | power_in | Positive reference (steering-diode top rail, tied to the TVS diode), internally common with pin 2. |
| 4 | I/O 2 | passive | Protected I/O line 2, with 7pF max (5pF typ) junction capacitance to ground and 3pF typ between I/O pins. |
| 5 | REF 2 | power_in | Ground reference (bottom rail of the steering diodes), internally common with pin 8. |
| 6 | I/O 3 | passive | Protected I/O line 3, with 7pF max (5pF typ) junction capacitance to ground and 3pF typ between I/O pins. |
| 7 | I/O 4 | passive | Protected I/O line 4, with 7pF max (5pF typ) junction capacitance to ground and 3pF typ between I/O pins. |
| 8 | REF 2 | power_in | Ground reference (bottom rail of the steering diodes), internally common with pin 5. |

## Key specifications

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

## CAD (KiCad official)

- Symbol: `SRDA3.3-4DR2G`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `srda3-3-4dr2g-etched.step` / `srda3-3-4dr2g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `srda3-3-4dr2g.step` / `srda3-3-4dr2g.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/8590919873558503424) (4 pp, sha256 `0d72d7db9c53591b`, 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/srda3-3-4dr2g-datasheet.pdf)