# ER304

**SUNMATE Elec** · Fast Recovery / High Efficiency Diodes · DO-27

ER304 from SUNMATE Elec, in a DO-27. 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 at the end marked with the cathode band; ER304 is rated 400V VRRM, 280V VRMS, 400V VDC and 3.0A average forward current. |
| 2 | A | passive | Anode, the lead opposite the cathode band; ER304 has 1.7V maximum forward voltage at 3.0A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | SUNMATE Elec |
| Package | DO-27 |
| Category | Diodes |
| 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 |
|---|---|---|---|---|---|---|---|
| Maximum recurrent peak reverse voltage | VRRM |  |  | 400 | V |  | 1 |
| Maximum RMS voltage | VRMS |  |  | 280 | V |  | 1 |
| Maximum DC blocking voltage | VDC |  |  | 400 | V |  | 1 |
| Maximum average forward rectified current | IF(AV) |  |  | 3 | A | 9.5mm lead length, @TA=75 | 1 |
| Maximum instantaneous forward voltage | VF |  |  | 1.25 | V | @ 3.0A | 1 |
| Operating junction temperature range | TJ | -55 |  | 150 | °C |  | 1 |
| Storage temperature range | TSTG | -55 |  | 150 | °C |  | 1 |

## CAD (KiCad official)

- Symbol: `ER304`
- Footprint: `Diode_THT:D_DO-27_P15.24mm_Horizontal`
- 3D model: DO-27 (KiCad packages3D, STEP)

## Provenance

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

- **Datasheet:** [SUNMATE Elec datasheet](docs/er304-datasheet.pdf) (2 pp, sha256 `2e0057de31627d9a`, retrieved 2026-10-22, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text), consensus `claude-sonnet-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/er304-datasheet.pdf)