The part number **DM19CA102JO3-SA-R02** refers to a high-reliability, silver mica capacitor typically manufactured by Cornell Dubilier (CDE) or similar specialized manufacturers. These components are renowned for their stability and precision in RF applications. --- ### 1. Technical Specifications Breakdown The part number follows a specific nomenclature that describes its physical and electrical characteristics: | Parameter | Specification | Description | | :--- | :--- | :--- | | **Series** | DM19 | Standard dipped silver mica case size (approx. 11.4 x 11.4 mm). | | **Temperature Coeff.** | CA | Characteristic C: Temp. coefficient of -20 to +100 ppm/°C. | | **Capacitance** | 102 | 1000 pF (10 followed by 2 zeros). | | **Tolerance** | J | ±5% precision. | | **Voltage Rating** | O3 | Typically represents 300V or 500V DC (varies by specific series table). | | **Termination** | SA | Silvered/Solderable leads, often indicating a specific lead spacing or finish. | | **Compliance** | R02 | Usually denotes RoHS compliance and specific packaging revision. | --- ### 2. Key Features of Silver Mica Technology Silver mica capacitors like the **DM19** series are selected for circuits where performance cannot be compromised. * **High Stability:** Extremely low capacitance change over time and temperature fluctuations. * **Low Loss:** They feature a very high Q-factor (low dissipation factor), making them ideal for high-frequency filters. * **Voltage Withstanding:** Excellent dielectric strength, capable of handling high voltage spikes without breakdown. * **Tight Tolerances:** While this specific part is ±5% (J), the technology allows for tolerances as low as ±0.5%. --- ### 3. Common Applications Due to their cost (higher than ceramic) and high performance, they are used in: 1. **RF Circuits:** Oscillators, tuned circuits, and transmitters. 2. **Audio Equipment:** High-end amplifiers where signal integrity is paramount. 3. **Test Equipment:** Calibration standards and precision timing circuits. 4. **Aerospace/Defense:** Situations requiring high reliability in harsh thermal environments. --- ### 4. Comparison: Mica vs. Ceramic (C0G/NP0) | Feature | Silver Mica (DM19) | Ceramic (C0G/NP0) | | :--- | :--- | :--- | | **Stability** | Excellent (Historical Standard) | Excellent (Modern Standard) | | **Size** | Larger (Dipped Radial) | Very Small (SMD/Radial) | | **Voltage** | Very High (up to 1000V+) | Low to Moderate | | **Cost** | High | Low |