The **440LQ47-R** is a specific type of ceramic disc capacitor, typically part of the **440L Series** manufactured by Vishay Cera-Mite. These components are designed for AC applications, specifically for electromagnetic interference (EMI) suppression. --- ### 1. Technical Specifications The part number follows a specific nomenclature that defines its electrical characteristics: | Feature | Specification | | :--- | :--- | | **Component Type** | Ceramic Disc Capacitor | | **Series** | 440L (High Voltage / Safety Grade) | | **Capacitance Value** | 470 pF (indicated by "47") | | **Safety Classification** | Class X1 / Y1 | | **Rated Voltage** | 500 VAC (X1), 500 VAC (Y1) | | **Dielectric Material** | Typically Y5U or U2J (depending on specific tolerance) | | **Mounting Type** | Through-hole (Radial Leads) | --- ### 2. Key Features and Applications The "R" suffix often indicates compliance with **RoHS** (Restriction of Hazardous Substances) standards. #### Safety Classifications * **X1 Class:** Designed for across-the-line applications where failure would not lead to electric shock but could cause a fire risk. * **Y1 Class:** Designed for line-to-ground applications. These have more stringent insulation requirements because a failure could lead to a fatal electric shock. #### Common Uses * **EMI/RFI Filtering:** Suppressing electrical noise in power supplies. * **Line Bypass:** Filtering transients from the AC mains. * **Antenna Coupling:** Protecting sensitive circuitry from high-voltage surges. --- ### 3. Physical Construction The device consists of a ceramic disc coated with silver on both sides. It is then encapsulated in a flame-retardant epoxy resin (usually UL 94 V-0 rated) to protect against moisture and mechanical stress. --- ### 4. Comparison with Standard Capacitors | Feature | 440LQ47-R (Safety Disc) | Standard Ceramic Disc | | :--- | :--- | :--- | | **Voltage Spikes** | Can withstand high impulse voltages | May puncture or short-circuit | | **Failure Mode** | Designed to fail "open" for safety | May fail "shorted" | | **Certification** | UL, CSA, VDE approved | No safety certifications |