The **6125FF7-R** is a high-performance, Surface Mount Device (SMD) fuse manufactured by **Eaton (formerly Bussmann)**. It belongs to the 6125FF series, known for its "Fast-Acting" (FF) characteristics. ### Technical Specifications Below are the primary electrical and physical parameters for the 6125FF7-R: | Parameter | Specification | | :--- | :--- | | **Current Rating** | 7 Amperes (7A) | | **Voltage Rating (AC)** | 125 Vac | | **Voltage Rating (DC)** | 72 Vdc | | **Interrupting Rating** | 50A @ 125Vac / 300A @ 72Vdc | | **Fuse Characteristic** | Fast-Acting (FF) | | **Package / Case** | 2410 (6125 Metric) | | **Mounting Type** | Surface Mount (SMD/SMT) | | **Operating Temperature** | -55°C to +125°C | --- ### Key Features * **Form Factor:** The "6125" designation refers to its physical size: **6.1mm x 2.5mm**. In the imperial system, this is equivalent to a **2410** footprint. * **Fast-Acting Protection:** Designed to open quickly in the event of an overcurrent or short-circuit, protecting sensitive downstream components like ICs and MOSFETs. * **Construction:** It features a brick-style ceramic body which provides excellent thermal stability and high "I²t" values (melting integral) despite its small size. * **Compliance:** The "-R" suffix indicates that the part is **RoHS compliant** (lead-free). --- ### Typical Applications This fuse is commonly used in industrial and consumer electronics where space is limited but high current protection is required: 1. **LCD Monitors and TVs:** Protecting backlight inverters. 2. **Power Supplies:** Secondary side protection in AC/DC adapters. 3. **Computing:** Laptops, servers, and storage system power rails. 4. **Medical Equipment:** Internal circuit protection for portable devices. --- ### Part Number Breakdown Understanding the nomenclature helps in identifying variants: | Prefix | Series | Amp Rating | RoHS | | :--- | :--- | :--- | :--- | | **6125** | **FF** | **7** | **-R** | | Size (6.1x2.5mm) | Fast-Acting | 7 Amperes | Lead-Free/RoHS |