## Technical Overview: HCM1305-4R7-R The **HCM1305-4R7-R** is a high-current, automotive-grade power inductor manufactured by **Eaton (formerly Bussmann)**. It belongs to the HCM series, which is specifically designed to handle high power densities and high-frequency applications. --- ### 1. Key Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 4.7 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 11.2 mΩ (Typical) / 13.5 mΩ (Max) | | **Rated Current (rms)** | 13.0 Amps | | **Saturation Current (Isat)** | 15.0 Amps | | **Operating Temperature** | -55°C to +125°C | | **Package / Case** | 13.8mm x 12.5mm x 5.0mm (SMD) | --- ### 2. Core Features and Construction * **Iron Powder Core:** The inductor uses a molded iron powder construction. This provides "soft saturation" characteristics, meaning the inductance drops gradually rather than abruptly as the current increases. * **Magnetically Shielded:** The design minimizes Electromagnetic Interference (EMI), making it suitable for noise-sensitive environments like automotive infotainment or telecommunications. * **Low Core Loss:** Optimized for high-frequency switching, reducing heat generation during operation. * **AEC-Q200 Qualified:** It meets the rigorous stress-test requirements for automotive electronics. --- ### 3. Application Use Cases This component is typically used in DC-DC converters and power supply modules where high current and reliability are critical. * **Automotive:** Engine Control Units (ECUs), LED lighting drivers, and Advanced Driver Assistance Systems (ADAS). * **Industrial:** High-current point-of-load (POL) converters. * **Computing:** Multi-phase voltage regulator modules (VRMs) for servers and high-end processors. --- ### 4. Part Number Breakdown The part number follows a specific nomenclature used by Eaton: | Segment | Meaning | | :--- | :--- | | **HCM** | Series Name (High Current Power Inductor) | | **1305** | Size Code (Approx. 13mm x 5mm height) | | **4R7** | Inductance Value (4.7 microhenries) | | **R** | RoHS Compliant / Lead-Free |