The **440LD55-R** is a high-voltage, ceramic disc capacitor manufactured by **Vishay Cera-Mite**. It is part of the 440L series, which are primarily designed for AC line applications and electromagnetic interference (EMI) suppression. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Capacitance** | 5,500 pF (5.5 nF) | | **Tolerance** | ± 20% | | **Voltage Rating** | 440 VAC / 125 VAC (UL/CSA/IEC Safety Standards) | | **Dielectric Material** | Ceramic (Class 2) | | **Mounting Type** | Through-Hole (Radial Disc) | | **Operating Temperature** | -30°C to +125°C | | **Safety Class** | X1 / Y1 or Y2 (Standard dependent) | --- ### 2. Physical Characteristics The "R" suffix often indicates compliance with environmental standards or specific lead configurations (RoHS compliance). * **Coating:** Encapsulated in flame-retardant epoxy resin (UL 94 V-0 rated). * **Terminals:** Radial tinned copper leads. * **Marking:** The body is marked with the manufacturer logo, capacitance value, and safety agency certifications (e.g., UL, VDE, CSA). --- ### 3. Applications and Usage These capacitors are "Safety Rated," meaning they are designed to fail in a way that does not lead to electric shock or fire when subjected to high-voltage surges. 1. **Across-the-line (Class X):** Used to reduce noise between the "Live" and "Neutral" lines. 2. **Line-to-Ground (Class Y):** Used to bypass noise from "Live" or "Neutral" to the chassis ground. 3. **EMI/RFI Filtering:** Essential for switch-mode power supplies (SMPS), motor controllers, and household appliances to comply with electromagnetic compatibility regulations. 4. **Antenna Coupling:** Used in radio and television circuits to isolate high-voltage DC while allowing AC signals to pass. --- ### 4. Circuit Symbol Representation In a schematic, this part is represented as a non-polarized capacitor, often with safety markings: ```text L (Line) o-------||-------o N (Neutral) 440LD55-R ``` ---