The part number **DM19CE102JO3-SA-R02** refers to a high-precision Silver Mica capacitor, typically manufactured by Cornell Dubilier (CDE). These components are known for their extreme stability, low loss, and reliability in RF (Radio Frequency) applications. --- ## 1. Technical Specifications Breakdown The alphanumeric code contains specific information regarding the capacitor's build and electrical properties: | Feature | Specification | Description | | :--- | :--- | :--- | | **Series** | DM19 | Standard dipped mica capacitor (Case size 19) | | **Capacitance Code** | 102 | 1000 pF (1.0 nF) | | **Tolerance** | J | ±5% | | **Voltage Rating** | 3 | 300 VDC | | **Operating Temp** | E | -55°C to +125°C | | **Characteristic** | C | Temp. Coefficient: -20 to +100 ppm/°C | --- ## 2. Key Internal Components ### Dielectric Material (Silver Mica) Unlike ceramic or electrolytic capacitors, this part uses **Muscovite mica**. Sheets of mica are coated with silver electrodes. This construction provides: * **Low Dissipation Factor:** Very little energy is lost as heat. * **High Q Factor:** Excellent for resonant circuits. * **Non-Aging:** Unlike ceramic capacitors, mica does not lose capacitance over time. ### Physical Packaging * **Dipped Coating:** The "SA" likely refers to the specific phenolic or epoxy coating used to protect the internal stack from moisture. * **Lead Type:** Usually features copper-clad steel leads (solderable) arranged in a radial configuration. --- ## 3. Applications Due to the precision of the **DM19** series, these parts are commonly found in: 1. **RF Oscillators:** Maintaining a stable frequency regardless of temperature shifts. 2. **Filter Networks:** Used in high-fidelity audio or radio tuning where tight tolerance is required. 3. **Pulse Power:** Handling high-speed voltage transitions without degradation. 4. **Calibration Equipment:** Serving as a stable reference capacitor. --- ## 4. Equivalent Comparison | Feature | Silver Mica (DM19) | C0G/NP0 Ceramic | | :--- | :--- | :--- | | **Stability** | Superior | High | | **Voltage Stress** | High Resistance | Moderate | | **Cost** | High | Low | | **Self-Inductance** | Very Low | Low |