The **MF-RX160-AP** is a specific model of Radial Leaded Polymer Positive Temperature Coefficient (PPTC) resettable fuse, manufactured by **Bourns**. These components are commonly referred to as "resettable fuses" or "polyfuses." --- ## 1. Technical Specifications The MF-RX series is designed to protect electrical circuits from overcurrent conditions. Unlike traditional fuses that blow and must be replaced, these "reset" once the fault is removed and the device cools down. | Feature | Specification | | :--- | :--- | | **Hold Current ($I_{hold}$)** | 1.60 Amps | | **Trip Current ($I_{trip}$)** | 3.20 Amps | | **Max Voltage ($V_{max}$)** | 60 Volts | | **Max Current ($I_{max}$)** | 40 Amps | | **Power Dissipation** | 1.5 Watts | | **Mounting Type** | Through-Hole (Radial Leaded) | | **Packaging** | Ammo Pack ("-AP" suffix) | --- ## 2. Key Characteristics ### Resettable Functionality The device is made of a conductive plastic combination. Under normal conditions, the particles form low-resistance paths. When an overcurrent occurs, the material heats up, expands, and becomes highly resistive, effectively cutting off the current. ### The "-AP" Suffix The suffix in the part number indicates the packaging style: * **MF-RX160**: The base part number. * **-AP**: Stands for **Ammo Pack**. This means the parts are taped and folded into a box for use with automatic insertion machinery, rather than being provided as loose bulk pieces. --- ## 3. Typical Applications The MF-RX160-AP is versatile and used in circuits where mid-range current protection is needed: * **Industrial Controls:** Protecting sensors and actuators. * **IEEE 1394 (Firewire) / USB Ports:** Preventing damage from shorted cables. * **Power Supplies:** Secondary side protection for transformers. * **Security Systems:** Overload protection for alarm panels and sirens. --- ## 4. Performance Considerations 1. **Ambient Temperature:** The hold current ($I_{hold}$) decreases as the surrounding temperature increases. Engineers must derate the component if it is used in a hot environment. 2. **Time to Trip:** At $5 \times I_{hold}$ (8.0A), this specific model typically trips in approximately **11.4 seconds**. 3. **Resistance:** Once tripped and reset, the device's "Post-Trip Resistance" ($R_{1max}$) will be slightly higher than its initial resistance ($R_{min}$).