The **440LD28-R** is a specific type of high-voltage ceramic disc capacitor. These components are primarily designed for use in AC applications, particularly for electromagnetic interference (EMI) suppression and safety-related circuitry. ### 1. Technical Specifications The following table outlines the key electrical and physical characteristics of the 440LD28-R: | Feature | Specification | | :--- | :--- | | **Manufacturer** | Vishay Cera-Mite | | **Capacitance** | 0.0028 µF (2.8 nF) | | **Voltage Rating** | 440 VAC (RMS) | | **Dielectric Type** | Ceramic (Class X1/Y1 or Y2 depending on series) | | **Tolerance** | Generally ±10% or ±20% | | **Mounting Type** | Through-hole (Radial Leads) | | **Temperature Coefficient** | Linear characteristic (often Y5U or similar) | --- ### 2. Key Features and Functions The 440LD series is engineered for durability and safety in high-stress environments. * **Safety Rating:** These are typically **Class X/Y safety capacitors**. * **Class X:** Used across-the-line (line-to-line). If they fail, there is a risk of fire but not electric shock. * **Class Y:** Used line-to-ground. These are designed to fail "open" to prevent the chassis of a device from becoming electrically "hot," protecting the user from shock. * **Flame Retardant:** The outer coating is usually made of flame-retardant epoxy resin (UL 94 V-0 rated). * **High Reliability:** Designed to withstand high-voltage impulses (surges) from the power line. ### 3. Common Applications The 440LD28-R is commonly found in the input stages of power electronics: 1. **EMI/RFI Filtering:** Suppressing high-frequency noise generated by switching power supplies. 2. **Antenna Coupling:** Used in radio and television circuits to isolate different stages while allowing signals to pass. 3. **Line Bypass:** Diverting transient voltage spikes to the ground. 4. **Power Supplies:** Found in AC-to-DC converters to clean the incoming mains power. --- ### 4. Part Number Breakdown (General Vishay Format) While codes can vary slightly, the structure generally follows this logic: | Segment | Meaning | | :--- | :--- | | **440L** | Series designation (High voltage AC safety) | | **D28** | Capacitance code (2.8 nF / 2800 pF) | | **-R** | RoHS Compliant (Lead-free) |