The **PJ-059A** is a common electronic component used for power delivery. Specifically, it is a **DC Power Jack** (also known as a barrel jack) designed for Through-Hole Mounting (THM) on Printed Circuit Boards (PCBs). --- ### 1. Technical Specifications The following table outlines the typical electrical and physical characteristics of the PJ-059A: | Feature | Specification | | :--- | :--- | | **Type** | DC Power Jack / Connector | | **Mounting Type** | Through-hole (PCB) | | **Center Pin Diameter** | 2.0 mm | | **Internal Diameter** | 5.5 mm (Standard) | | **Voltage Rating** | 24V DC | | **Current Rating** | 2.5A to 5A (varies by manufacturer) | | **Contact Resistance** | ≤ 30mΩ | | **Insulation Resistance** | ≥ 100MΩ (500V DC) | | **Operating Temp** | -25°C to +85°C | --- ### 2. Pin Configuration & Internal Structure The PJ-059A typically features **3 pins**. Understanding these is crucial for proper circuit design: 1. **Center Pin (Pin 1):** Usually connected to the Positive (+) voltage rail. 2. **Shunt/Sleeve (Pin 2):** The outer contact, usually connected to Ground (GND). 3. **Switch Pin (Pin 3):** A normally closed (NC) contact. When a plug is inserted, it physically disconnects Pin 3 from Pin 2. This is often used to automatically disconnect an internal battery when an external power supply is plugged in. --- ### 3. Usage and Applications Because of its small footprint and standard 2.0mm pin size, it is widely used in: * **Consumer Electronics:** Routers, modems, and small audio devices. * **Prototyping:** Popular in Arduino and DIY electronics projects. * **Power Adapters:** Compatible with standard "wall wart" AC/DC adapters. --- ### 4. Footprint Example (Standard) When designing a PCB for this part, the layout generally follows this logic: ```markdown [ PCB TOP VIEW ] _______ | 1 | <-- Center Pin (Rear) | | | 3 2 | <-- 3: Switch Pin / 2: Sleeve Pin |_______| (O) <-- Barrel Entry Point ``` ---