The **312-R** typically refers to a high-performance **Surface Mount Device (SMD) Power Inductor**, commonly part of the **312 Series**. These components are essential in power management circuits for filtering and energy storage. --- ### 1. Key Technical Specifications The "312-R" designation (specifically from manufacturers like Coiltronics/Eaton or similar SMD series) usually follows these general parameters: | Parameter | Typical Value / Range | | :--- | :--- | | **Inductance Range** | 0.47µH to 1000µH | | **Current Rating (Isat)** | High (often up to 50A depending on size) | | **DCR (DC Resistance)** | Very Low (mΩ range) | | **Operating Temp** | -40°C to +125°C | | **Material** | Ferrite Core | --- ### 2. Physical Construction The **R** suffix often denotes **RoHS compliance** (Lead-free) or specific **Reel** packaging for automated pick-and-place assembly. * **Shielding:** Most 312-R parts are magnetically shielded to reduce Electromagnetic Interference (EMI), which is critical for densely packed PCBs. * **Footprint:** They feature a low-profile, square or rectangular SMD base with flat metal pads for high-reliability soldering. --- ### 3. Functional Applications These parts are primarily found in high-frequency DC-DC converters. * **Voltage Regulator Modules (VRMs):** Used in laptops and servers to step down voltage for CPUs. * **Energy Storage:** Acts as a reservoir in switching power supplies. * **Noise Filtering:** Used in input/output filters to smooth out ripple current and prevent electrical noise from affecting other components. --- ### 4. Part Number Breakdown (Example) If looking at a full part number like `DR127-312-R`: 1. **DR127:** Refers to the physical dimensions (e.g., 12.5mm x 12.5mm x 7mm). 2. **312:** The inductance code (where 312 usually represents 3.1µH or a specific internal series designator). 3. **R:** Indicates RoHS compliance. --- ### 5. Alternative Interpretations While usually an inductor, "312-R" can occasionally appear in other contexts: * **Resistors:** A 312-R might refer to a **312 Ohm** resistor in specific military or legacy naming conventions. * **Connectors:** Some RF or circular connectors use "312" as a shell size or series indicator. ---