The **CK45-R3FD331K** is a high-voltage ceramic disc capacitor manufactured by TDK. It is specifically designed for use in power supply circuits where high reliability and durability under high voltage are required. --- ### 1. Technical Specifications Table | Feature | Specification | | :--- | :--- | | **Part Number** | CK45-R3FD331K | | **Capacitance** | 330 pF (Picofarads) | | **Tolerance** | ±10% (K) | | **Rated Voltage** | 3000V DC (3kV) | | **Dielectric Material** | R (Class II - High Dielectric Constant) | | **Operating Temperature** | -25°C to +125°C | | **Mounting Type** | Through-hole (Radial Leads) | | **Coating** | Flame-retardant epoxy resin (UL94V-0) | --- ### 2. Breakdown of the Part Number The part number follows TDK's standardized coding system: * **CK45**: Series name (High Voltage Ceramic Capacitors). * **R**: Temperature characteristics (indicates capacitance change over temperature range). * **3F**: Rated Voltage code (3F represents 3000V DC). * **D**: Lead shape/spacing (typically denotes radial lead configuration). * **331**: Capacitance value. The first two digits (33) are significant figures; the third digit (1) is the multiplier ($10^1$). $33 \times 10 = 330$ pF. * **K**: Tolerance code (±10%). --- ### 3. Key Electronic Characteristics * **High Voltage Resistance:** Designed to withstand high surges, making it ideal for the primary side of switching power supplies. * **Insulation Resistance:** Maintains very high resistance at rated voltage to prevent leakage current. * **Durability:** The Class II dielectric provides a balance between high capacitance density and stability, though it is more sensitive to temperature and voltage fluctuations than Class I (C0G/NP0) capacitors. --- ### 4. Common Applications Due to its 3kV rating, this component is commonly found in: 1. **Switching Power Supplies (SMPS):** Used for snubber circuits and noise filtering. 2. **Inverters:** High-voltage DC filtering. 3. **Displays (CRT/LCD Backlights):** High-voltage ballast and resonance circuits. 4. **Lighting:** Electronic ballasts for fluorescent or HID lamps.