The **MJS 150-R** is a high-performance **Surface Mount Device (SMD) Square Fuse** belonging to the MJS series manufactured by Bel Fuse Inc. It is designed for overcurrent protection in compact electronic circuits. ### 1. Technical Specifications Below are the primary electronic characteristics of the MJS 150-R: | Parameter | Specification | | :--- | :--- | | **Current Rating** | 150mA (0.15A) | | **Voltage Rating (AC)** | 125V | | **Voltage Rating (DC)** | 125V | | **Fuse Type** | Slow Blow / Time Delay | | **Interrupting Rating** | 50A @ 125V AC/DC | | **Resistance (Cold)** | ~1.65 Ohms | | **Melting Integral ($I^2t$)** | 0.016 $A^2s$ | --- ### 2. Key Electronic Features * **Time-Delay Characteristic:** Unlike "Fast-Acting" fuses, the MJS 150-R is a **Slow Blow** fuse. This means it can withstand brief temporary current surges (inrush currents) without blowing, which is essential for circuits with capacitors or motors. * **Surface Mount Design (SMD):** It uses a square ceramic body with metal end caps, designed for automated "pick and place" assembly on Printed Circuit Boards (PCBs). * **Wide Temperature Range:** Typically rated for operation between **-55°C to +125°C**, making it suitable for industrial environments. * **RoHS Compliant:** The "-R" suffix in the part number indicates that the component is **RoHS 6 compliant** (lead-free), meeting international environmental safety standards. --- ### 3. Applications and Usage The MJS 150-R is commonly integrated into the following electronic systems: 1. **Telecommunications:** Protection for line cards and networking equipment. 2. **Power Supplies:** Used on the low-current side of DC-DC converters. 3. **Consumer Electronics:** Protecting sensitive ICs in laptops, chargers, and monitors. 4. **Industrial Controllers:** Safeguarding PLC inputs and small sensor arrays. ### 4. Circuit Symbol and Footprint In a schematic, this part is represented by the standard fuse symbol. On a PCB, it follows a standard square SMD footprint (approximately 6.1mm x 2.6mm). ```text PCB Footprint (Approximate): _______ | [ ] | <-- Ceramic Body |_______| [Ref: 2410 / 6125 Metric] ```