## Overview of JS0404FP4-R The **JS0404FP4-R** belongs to a series of **DIP Switches** (Dual In-line Package switches), specifically designed for surface mount applications. These components are used to manually set binary codes or configurations on a printed circuit board (PCB). --- ### 1. Technical Specifications | Parameter | Value / Description | | :--- | :--- | | **Component Type** | DIP Switch | | **Actuator Style** | Piano (Side Actuated) | | **Number of Positions** | 4 Positions | | **Circuit Type** | SPST (Single Pole Single Throw) | | **Mounting Type** | Surface Mount (SMT / SMD) | | **Pitch** | 1.27mm (Half Pitch) | | **Contact Rating** | 25mA @ 24VDC | | **Operating Temperature** | -40°C to +85°C | --- ### 2. Key Physical Features * **Piano Actuator:** Unlike standard slide switches, the piano-style actuator allows for switching from the side, which is ideal for boards that are stacked or housed in tight enclosures where top access is restricted. * **Half Pitch Design:** The 1.27mm spacing is half the size of standard DIP switches (2.54mm), making it suitable for high-density electronic assemblies like IoT devices or handheld modules. * **Gold-Plated Contacts:** Most parts in this series use gold plating to ensure high reliability and prevent oxidation over long periods of inactivity. --- ### 3. Functional Applications The JS0404FP4-R is primarily used in electronics for: 1. **Address Setting:** Assigning a unique ID to a device on a shared bus (e.g., RS-485 or DMX networks). 2. **Configuration:** Enabling or disabling specific hardware features without changing the firmware. 3. **Mode Selection:** Switching between different modes of operation (e.g., Test Mode vs. Normal Mode). --- ### 4. PCB Footprint Example When designing a PCB for this part, the landing pattern usually follows a standard 4-position SMT layout: ```text [ ] [ ] [ ] [ ] <- Terminals 1 2 3 4 ------------------------- | [ ] [ ] [ ] [ ] | <- Piano Actuators ------------------------- 1' 2' 3' 4' [ ] [ ] [ ] [ ] <- Terminals ```