# BAS321JX

**Nexperia** · Switching Diodes · SOD-323

BAS321JX from Nexperia, in a SOD-323. 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 of the high-voltage switching diode; reverse voltage VR up to 200 V (VRRM 250 V) and forward current IF up to 250 mA. |
| 2 | A | passive | Anode of the high-voltage switching diode; forward voltage VF max 1.25 V at IF = 200 mA, Tj = 25 °C. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Nexperia |
| Package | SOD-323 |
| 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 |
|---|---|---|---|---|---|---|---|
| Repetitive peak reverse voltage | VRRM |  |  | 250 | V |  | 3 |
| Reverse voltage | VR |  |  | 200 | V |  | 3 |
| Forward current | IF |  |  | 250 | mA | Device mounted on FR4 PCB, standard footprint | 3 |
| Non-repetitive peak forward current | IFSM |  |  | 13 | A | tp = 50 µs; Tj(init) = 25 °C; square wave | 3 |
| Non-repetitive peak forward current | IFSM |  |  | 9 | A | tp = 100 µs; Tj(init) = 25 °C; square wave | 3 |
| Non-repetitive peak forward current | IFSM |  |  | 3 | A | tp = 10 ms; Tj(init) = 25 °C; square wave | 3 |
| Repetitive peak forward current | IFRM |  |  | 625 | mA | tp ≤ 0.5 ms; δ ≤ 0.25 | 3 |
| Total power dissipation | Ptot |  |  | 420 | mW | Tamb ≤ 25 °C; FR4 PCB, standard footprint | 3 |
| Total power dissipation | Ptot |  |  | 660 | mW | Tamb ≤ 25 °C; FR4 PCB, mounting pad for cathode 1 cm2 | 3 |
| Junction temperature | Tj |  |  | 150 | °C |  | 3 |
| Ambient temperature | Tamb | -55 |  | 150 | °C |  | 3 |
| Storage temperature | Tstg | -65 |  | 150 | °C |  | 3 |
| Thermal resistance junction to ambient | Rth(j-a) |  |  | 300 | K/W | FR4 PCB, standard footprint | 3 |
| Thermal resistance junction to ambient | Rth(j-a) |  |  | 190 | K/W | FR4 PCB, mounting pad for cathode 1 cm2 | 3 |
| Thermal resistance junction to solder point | Rth(j-sp) |  |  | 40 | K/W | Soldering point of cathode tab | 3 |
| Forward voltage | VF |  |  | 1 | V | IF = 100 mA; tp ≤ 300 µs; δ ≤ 0.02; Tj = 25 °C | 5 |
| Forward voltage | VF |  |  | 1.25 | V | IF = 200 mA; tp ≤ 300 µs; δ ≤ 0.02; Tj = 25 °C | 5 |
| Reverse current | IR |  |  | 100 | nA | VR = 200 V; pulsed; Tj = 25 °C | 5 |
| Reverse current | IR |  |  | 100 | µA | VR = 200 V; pulsed; Tj = 150 °C | 5 |
| Diode capacitance | Cd |  |  | 2 | pF | VR = 0 V; f = 1 MHz; Tj = 25 °C | 5 |
| Reverse recovery time | trr |  |  | 50 | ns | IF = 30 mA; IR = 30 mA; RL = 100 Ω; IR(meas) = 3 mA; Tj = 25 °C | 5 |

## CAD (KiCad official)

- Symbol: `BAS321JX`
- Footprint: `Diode_SMD:D_SOD-323`
- 3D model: SOD-323 (KiCad packages3D, STEP)
- 3D model files: `bas321jx-etched.step` / `bas321jx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bas321jx.step` / `bas321jx.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Nexperia datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8589838226090323968) (12 pp, sha256 `8da037e25448aba1`, 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/bas321jx-datasheet.pdf)