# RB491D

**Changjing** · Schottky Diodes · SOT-23

RB491D from Changjing, in a SOT-23. 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 | A | passive | Anode of the single Schottky diode (symbol shows pin 1 on the anode side), rated for 1 A mean rectifying current and 20 V DC reverse voltage. |
| 2 | NC | unconnected | Not connected to the diode; the package symbol shows pin 2 as an open circle with no connection. |
| 3 | K | passive | Cathode of the single Schottky diode (symbol shows the diode pointing toward pin 3), with 0.45 V max forward voltage at IF=1 A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-23 |
| Category | Diodes |
| Pins | 3 |

## 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 voltage | VF |  |  | 0.45 | V | IF=1A | 1 |
| Reverse current | IR |  |  | 200 | μA | VR=20V | 1 |
| Peak reverse voltage | VRM |  |  | 25 | V |  | 1 |
| DC reverse voltage | VR |  |  | 20 | V |  | 1 |
| Mean rectifying current | IF |  |  | 1 | A |  | 1 |
| Peak forward surge current | IFSM |  |  | 3 | A |  | 1 |
| Junction temperature | Tj |  |  | 150 | ℃ |  | 1 |
| Storage temperature | Tstg | -55 |  | 150 | ℃ |  | 1 |

## CAD (KiCad official)

- Symbol: `RB491D`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `rb491d-etched.step` / `rb491d-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `rb491d.step` / `rb491d.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Changjing datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8586171831435214848) (1 pp, sha256 `c0f2cffc8d6d6e0e`, retrieved 2026-10-16, 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/rb491d-datasheet.pdf)