# BAS40-04Q

**Yangzhou Yangjie Elec Tech** · Schottky Diodes · SOT-23(TO-236)

BAS40-04Q from Yangzhou Yangjie Elec Tech, in a SOT-23(TO-236). 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 | A1 | passive | Anode of the first Schottky diode (marking 44, BAS40-04Q dual series configuration); 40V VRRM, 120mA IFAV per the datasheet. |
| 2 | K2 | passive | Cathode of the second Schottky diode in the BAS40-04Q series pair; 40V VRRM, 120mA IFAV per the datasheet. |
| 3 | K1/A2 | passive | Common node joining the cathode of the first diode and the anode of the second diode in the BAS40-04Q series configuration. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Yangzhou Yangjie Elec Tech |
| Package | SOT-23(TO-236) |
| 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 |
|---|---|---|---|---|---|---|---|
| Peak Repetitive Reverse Voltage | VRRM |  |  | 40 | V |  | 1 |
| Average Forward Current | IFAV |  |  | 120 | mA |  | 1 |
| Non-repetitive Peak Forward Surge Current | IFSM |  |  | 0.6 | A | square wave tp<10ms | 1 |
| Power Dissipation | PD |  |  | 200 | mW |  | 1 |
| Thermal Resistance Junction to Ambient | RthJA |  |  | 500 | ℃/W | Junction to Ambient | 1 |
| Junction Temperature | Tj | -55 |  | 150 | ℃ |  | 1 |
| Storage Temperature Range | Tstg | -55 |  | 150 | ℃ |  | 1 |
| Reverse Breakdown Voltage | V(BR)R | 40 |  |  | V | IR=10uA | 2 |
| Forward Voltage | VF |  |  | 0.38 | V | IF=1.0mA | 2 |
| Forward Voltage | VF |  |  | 1 | V | IF=40mA | 2 |
| Reverse Current | IR |  |  | 0.2 | μA | VR=30V | 2 |
| Junction Capacitance | CJ |  |  | 5 | pF | VR=0 V, f=1MHZ | 2 |
| Reverse Recovery Time | trr |  |  | 5 | ns | IF=IR=5mA,Irr=0.5mA,RL=100Ω | 2 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| housing |  | black | 4. Body color: Black | 3 |
| contacts |  | tin | ● Terminals: Tin plated leads, solderable per J-STD-002 and JESD22-B102 | 1 |

## CAD (KiCad official)

- Symbol: `BAS40-04Q`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23(TO-236) (KiCad packages3D, STEP)
- 3D model files: `bas40-04q-etched.step` / `bas40-04q-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bas40-04q.step` / `bas40-04q.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Yangzhou Yangjie Elec Tech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8589835008144662528) (4 pp, sha256 `0d43fbeee6ea1172`, 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/bas40-04q-datasheet.pdf)