Based on the part number provided, this component is a **High-Voltage Ceramic Disc Capacitor** manufactured by **Dentsu** (often associated with high-precision electronic components). Below is a breakdown of the specifications and technical details for this specific part. --- ### 1. Part Number Decoder The alphanumeric code represents specific electrical characteristics: | Code Segment | Meaning | Description | | :--- | :--- | :--- | | **DM05** | Series/Size | Typical disc diameter (approx. 5mm to 6mm). | | **EY** | Temp. Coefficient | Indicates the dielectric material stability (e.g., Y5P or similar). | | **151** | Capacitance | **150 pF** (15 followed by one zero). | | **D** | Tolerance | Typically ±0.5pF or ±5% (depending on specific series). | | **O3** | Voltage Rating | Rated for **3kV (3000V DC)**. | | **ST** | Lead/Style | Straight Lead, Taped/Bulk. | | **R02** | RoHS/Revision | RoHS compliant version 02. | --- ### 2. Technical Specifications This component is designed for high-stress electrical environments where voltage spikes are common. * **Capacitance:** 150 pF * **Voltage Rating:** 3,000V DC (3kV) * **Type:** Ceramic Disc * **Mounting Type:** Through-Hole (THT) * **Dielectric Class:** Class 2 (High stability for high-voltage applications) --- ### 3. Key Applications Due to its high voltage rating and small capacitance, the **DM05EY151DO3** is commonly used in: 1. **Snubber Circuits:** Used in switching power supplies to absorb inductive "kickback" and protect transistors. 2. **Lighting Ballasts:** Found in LED drivers and fluorescent ballasts to handle high-voltage ignition pulses. 3. **High-Voltage Coupling:** Used to pass AC signals while blocking high DC voltages in RF or power circuits. 4. **CRT/Display Equipment:** Found in older television or monitor circuits where kilovolt levels are present. --- ### 4. Precautions for Use * **Voltage Derating:** While rated for 3kV, it is best practice to operate the capacitor at 50-60% of its rated voltage for long-term reliability. * **Lead Spacing:** Ensure the PCB layout accounts for the specific pitch (distance between legs) to prevent arcing across the board surface. * **Heat Sensitivity:** During soldering, excessive heat can crack the ceramic dielectric.