The **PCF25-R** is a high-performance, thick film chip resistor, typically manufactured by companies like **KOA Speer** or similar electronic component leaders. The "PCF" series generally refers to precision resistors designed for high stability and reliability. --- ### 1. Key Technical Specifications Below is a breakdown of the typical electronic characteristics of the PCF25-R series: | Feature | Specification (Typical) | | :--- | :--- | | **Component Type** | Thick Film Chip Resistor | | **Power Rating** | 0.25 Watts (1/4 W) at 70°C | | **Resistance Range** | 10Ω to 1MΩ (varies by specific model) | | **Tolerance** | ±0.5%, ±1%, or ±5% | | **Temperature Coefficient (TCR)** | ±100 ppm/°C to ±200 ppm/°C | | **Max Working Voltage** | 200V | | **Operating Temperature** | -55°C to +155°C | --- ### 2. Physical Construction The "25" in PCF25 usually denotes the physical size, corresponding to a **1206** imperial package (3216 metric). * **Substrate:** High-purity Alumina ($Al_2O_3$) ceramic. * **Resistive Layer:** Metal glaze (thick film) fired onto the substrate. * **Protective Coating:** Glass or epoxy overcoat for environmental protection. * **Terminations:** Lead-free (Sn) finish over a Nickel (Ni) barrier to prevent silver leaching during soldering. --- ### 3. Part Number Decoding While specific manufacturers vary, a part number like `PCF25-R-1002-F` usually breaks down as follows: 1. **PCF25:** Series name and package size (1206 / 0.25W). 2. **R:** Often indicates a specific stability class or "RoHS Compliant" status. 3. **1002:** The resistance value (100 + 2 zeros = 10,000Ω or 10kΩ). 4. **F:** The tolerance code (F = ±1%, J = ±5%, D = ±0.5%). --- ### 4. Common Applications Due to its 0.25W power rating and precision, the PCF25-R is commonly found in: * **Power Supplies:** Used as sense resistors or in feedback loops. * **Industrial Controls:** High-reliability circuits requiring thermal stability. * **Automotive Electronics:** Sensors and ECU units. * **Consumer Electronics:** General purpose current limiting and voltage division.