## SD3114-331-R: Technical Overview The **SD3114-331-R** is a high-power density, low-profile, shielded drum core inductor manufactured by **Eaton (formerly Cooper Bussmann)**. It belongs to the SD3114 series, which is specifically designed for space-constrained applications requiring high efficiency. --- ### 1. Key Technical Specifications | Parameter | Value | Details | | :--- | :--- | :--- | | **Inductance** | 330 µH | Measured at 100 kHz, 0.1 Vrms | | **Tolerance** | ±20% | Standard for power inductors | | **Current Rating (Irms)** | 0.224 A | Based on a 40°C temperature rise | | **Saturation Current (Isat)** | 0.246 A | Point where inductance drops by ~30% | | **DC Resistance (DCR)** | 3.51 Ω | Typical resistance at 20°C | | **Shielding** | Yes | Magnetic shielding to reduce EMI | | **Operating Temp** | -40°C to +125°C | Includes self-heating | --- ### 2. Physical Characteristics The "3114" in the part number refers to its physical dimensions, which are crucial for PCB layout: * **Footprint:** 3.1mm x 3.1mm * **Height:** 1.4mm (Max) * **Construction:** Ferrite drum core with a ferrite sleeve (shielded). * **Termination:** Matte tin over copper. --- ### 3. Electronic Functionality The SD3114-331-R serves several critical roles in electronic circuits: 1. **Energy Storage:** In DC-DC converters (Buck, Boost, or SEPIC), it stores energy in its magnetic field during the "on" cycle and releases it during the "off" cycle. 2. **EMI Suppression:** Because it is **shielded**, the magnetic flux is contained within the component. This prevents the inductor from interfering with nearby sensitive traces and helps the device pass electromagnetic compatibility (EMC) testing. 3. **Filtering:** It acts as a low-pass filter when paired with capacitors, smoothing out high-frequency ripple current from switching power supplies to provide a steady DC voltage. --- ### 4. Typical Applications Due to its small size and 330 µH inductance value, this part is commonly found in: * **Mobile Devices:** Smartphones, tablets, and wearables. * **LCD Displays:** Backlight drivers and panel power. * **Portable Medical Equipment:** Small diagnostic tools. * **IoT Sensors:** Battery-powered devices requiring efficient power management. --- ### 5. Part Number Breakdown | Segment | Meaning | | :--- | :--- | | **SD** | Series name (Shielded Drum) | | **3114** | Dimensions (3.1 x 3.1 x 1.4 mm) | | **331** | Inductance code (33 + one zero = 330 µH) | | **-R** | RoHS compliant |