The **MF-RHT200-2** is a specialized electronic component known as a **Polymer Positive Temperature Coefficient (PPTC)** resettable fuse, manufactured by Bourns. It is specifically designed for high-temperature environments, such as automotive or industrial applications. --- ### 1. Technical Specifications The following table summarizes the key electrical characteristics of the MF-RHT200-2: | Parameter | Value / Specification | | :--- | :--- | | **Hold Current ($I_{hold}$)** | 2.0 Amperes | | **Trip Current ($I_{trip}$)** | 3.8 Amperes | | **Max Voltage ($V_{max}$)** | 16 Volts DC | | **Max Current ($I_{max}$)** | 100 Amperes | | **Power Dissipation ($P_d$)** | 1.4 Watts (Typical) | | **Operating Temp Range** | -40°C to +125°C | | **Mounting Type** | Radial Leaded (Through-hole) | --- ### 2. Functional Principle The device operates based on the physical properties of a conductive polymer composite: 1. **Normal Operation:** At rated currents, the conductive particles within the polymer form low-resistance chains, allowing current to flow freely. 2. **Fault Condition:** If an overcurrent or overtemperature event occurs, the polymer heats up and expands. 3. **Tripping:** This expansion breaks the conductive chains, causing the resistance to increase exponentially (the "tripped" state), effectively cutting off the circuit. 4. **Resetting:** Once the fault is cleared and the device cools down, the polymer contracts, the chains reconnect, and the fuse resets to a low-resistance state. --- ### 3. Key Features & Applications The "RHT" series is distinct from standard PPTCs due to its thermal resilience. * **High Temperature Performance:** Unlike standard fuses that trip early in hot environments, this part is rated for operation up to **125°C**, making it ideal for engine compartments. * **AEC-Q200 Compliance:** It is typically tested to automotive standards for vibration, thermal shock, and mechanical integrity. * **Circuit Protection:** Used primarily to protect against: * Short circuits. * Overload conditions in motor circuits. * Electronic Control Unit (ECU) input protection. --- ### 4. Comparison: Fuse vs. PPTC While a standard fuse is a "one-time" component, the MF-RHT200-2 offers different logistics for circuit design: ```markdown - Standard Fuse: Blows and must be replaced manually. - MF-RHT200-2: "Trips" and resets automatically after power is cycled and heat dissipates. ```