# RPI-221A

**ROHM Semicon** · Photointerrupters - Slot Type - Transistor Output · DIP-4

RPI-221A from ROHM Semicon, in a DIP-4. 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 | Cathode | passive | LED (infrared emitter) cathode; max forward current 50 mA, reverse voltage 5 V, VF 1.3 V typ at IF=50 mA. |
| 2 | Anode | passive | LED (infrared emitter) anode; max forward current 50 mA, power dissipation 80 mW. |
| 3 | Collector | passive | Phototransistor collector; VCEO max 30 V, collector current max 30 mA, collector power dissipation 80 mW. |
| 4 | Emitter | passive | Phototransistor emitter; emitter-collector voltage max 4.5 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ROHM Semicon |
| Package | DIP-4 |
| Category | Optoelectronics |
| Pins | 4 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Forward current | IF |  |  | 50 | mA |  | 1 |
| Reverse voltage | VR |  |  | 5 | V |  | 1 |
| Power dissipation | PD |  |  | 80 | mW |  | 1 |
| Collector-emitter voltage | VCEO |  |  | 30 | V |  | 1 |
| Emitter-collector voltage | VECO |  |  | 4.5 | V |  | 1 |
| Collector current | IC |  |  | 30 | mA |  | 1 |
| Collector power dissipation | PC |  |  | 80 | mW |  | 1 |
| Operating temperature | Topr | -25 |  | 85 | °C |  | 1 |
| Storage temperature | Tstg | -30 |  | 85 | °C |  | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | 0.4 | V | IF =20mA, IC=0.1mA | 2 |
| Peak light emitting wavelength | λp |  | 950 |  | nm |  | 2 |
| Maximum sensitivity wavelength | λp |  | 800 |  | nm |  | 2 |

## CAD (KiCad official)

- Symbol: `RPI-221A`
- Footprint: `Package_DIP:DIP-4_W7.62mm`
- 3D model: DIP-4 (KiCad packages3D, STEP)
- 3D model files: `rpi-221a-etched.step` / `rpi-221a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `rpi-221a.step` / `rpi-221a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [ROHM Semicon datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588925847646846976) (6 pp, sha256 `d87b2e7329011e0d`, retrieved 2026-10-15, 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/rpi-221a-datasheet.pdf)