The part number **DM19EE151JO3-SA-R02** refers to a high-reliability **Silver Mica Capacitor** manufactured by Cornell Dubilier (CDE). These capacitors are known for their exceptional stability, low loss, and high precision in RF (Radio Frequency) and timing applications. --- ### 1. Technical Specifications Breakdown | Parameter | Specification | | :--- | :--- | | **Capacitance** | 150 pF (Picofarads) | | **Tolerance** | ±5% (indicated by 'J') | | **Voltage Rating** | 500 VDC (Standard for DM19 series) | | **Dielectric Material** | Silver Mica | | **Operating Temperature** | -55°C to +125°C | | **Case Type** | Dipped Mica (DM19 size) | | **Termination** | Standard Lead-Free / RoHS Compliant | --- ### 2. Part Number Nomenclature Analysis Understanding the alphanumeric code helps identify the physical and electrical characteristics: * **DM19**: Refers to the physical case size and style. DM19 is a standard industry size for mica capacitors, roughly 17.5mm x 16.3mm. * **E**: Temperature coefficient characteristic (Standard stability). * **151**: Capacitance value in pF. The first two digits (15) are significant figures, and the third (1) is the multiplier ($10^1$). So, $15 \times 10 = 150$ pF. * **J**: Tolerance code ($J = \pm 5\%$). * **O3**: Internal manufacturer sub-code relating to lead spacing or specific dielectric thickness. * **SA**: Specific finish or packaging code (often denotes "Straight Leads" or "Ammo Pack"). * **R02**: Revision or RoHS compliance identifier. --- ### 3. Key Characteristics * **High Stability:** Silver mica capacitors are famous for having very low drift over time and temperature. * **Low Dissipation Factor:** They exhibit very low ESR (Equivalent Series Resistance), making them efficient at high frequencies. * **Voltage Handling:** The 500V rating allows it to be used in tube amplifiers, transmitters, and power supply filtering. * **Precision:** Unlike ceramic capacitors (like Y5V or Z5U), the capacitance does not change significantly with applied voltage. --- ### 4. Common Applications These parts are typically found in specialized circuitry where precision is paramount: 1. **RF Oscillators:** Used to maintain a steady frequency. 2. **Filter Networks:** High-Q filters for radio and telecommunications. 3. **Timing Circuits:** Where RC time constants must remain exact despite temperature fluctuations. 4. **Audio Equipment:** Used in high-end guitar amplifiers and hi-fi audio for their "transparent" sonic qualities.