The **5TTP 1.25-R** is a specific type of electronic protection component, categorized as a **Time-Lag (Slow Blow) Radial Lead Micro Fuse**. It is manufactured by **Bel Fuse Inc.** and is widely used in power supplies and consumer electronics to protect circuits from overcurrent conditions. --- ### 1. Key Technical Specifications The following table outlines the primary electrical and physical characteristics of this part: | Parameter | Specification | | :--- | :--- | | **Current Rating** | 1.25 Amperes | | **Voltage Rating (AC)** | 250 Volts | | **Fuse Type** | Time-Lag (Slow Blow) / T-Type | | **Package / Case** | Radial Lead (Through-Hole) | | **Body Material** | Thermoplastic (typically black or brown) | | **Operating Temperature** | -55°C to +125°C | | **Breaking Capacity** | 35A @ 250V AC | --- ### 2. Detailed Component Breakdown #### A. Time-Lag (Slow Blow) Characteristic The "T" in the part number signifies a **Time-delay** characteristic. Unlike "Fast-Acting" fuses, the 5TTP 1.25-R is designed to withstand temporary high-current surges (inrush current) that occur when a device first powers on. It will only blow if the overcurrent persists for a specific duration, preventing "nuisance blowing." #### B. Radial Lead Form Factor The "TP" indicates a radial lead design. This means the two wires (leads) protrude from the bottom of the fuse body. This design is optimized for: * **PCB Mounting:** Small footprint on printed circuit boards. * **Automated Assembly:** Easy to insert using standard through-hole machinery. #### C. Safety Compliance This component is usually compliant with international safety standards, including: * **UL / CSA:** Certified for safety in North American markets. * **RoHS 6:** The "-R" suffix indicates that the part is **RoHS Compliant**, meaning it is free from hazardous substances like lead. --- ### 3. Common Applications Due to its 1.25A rating and slow-blow nature, it is frequently found in: * **Switching Power Supplies (SMPS):** Protecting the input stage. * **LED Lighting Drivers:** Managing the initial surge of capacitors. * **Battery Chargers:** Safeguarding against internal component failure. * **Consumer Electronics:** TV sets, monitors, and audio equipment. --- ### 4. Part Number Decoding | Segment | Meaning | | :--- | :--- | | **5TTP** | Bel Fuse Series (Radial, Time-Lag) | | **1.25** | Rated Amperage (1.25 Amps) | | **-R** | RoHS Compliant |