## Detailed Analysis of HC1-1R7-R The **HC1-1R7-R** is a high-current, power inductor belonging to the **HC1 series** manufactured by Eaton (formerly Cooper Bussmann/Coiltronics). It is specifically designed for high-frequency, high-current applications where stability and efficiency are critical. --- ### 1. Technical Specifications The part number itself follows a specific nomenclature that defines its core properties: | Parameter | Specification | | :--- | :--- | | **Inductance** | 1.7 µH | | **Tolerance** | ±20% | | **Rated Current (Irms)** | 18.0 Amps | | **Saturation Current (Isat)** | 28.0 Amps | | **DC Resistance (DCR)** | 2.5 mΩ (Max) | | **Operating Temperature** | -40°C to +125°C | | **Mounting Type** | Surface Mount (SMD) | --- ### 2. Construction and Materials The HC1 series utilizes advanced materials to handle significant power in a small footprint: * **Core Material:** Powered iron or alloy powder, which provides a soft saturation characteristic (the inductance doesn't drop off instantly as current increases). * **Packaging:** It is a shielded construction, which minimizes Electromagnetic Interference (EMI) with surrounding components. * **Termination:** Lead-free and RoHS compliant, typically using matte tin plating over copper. --- ### 3. Key Applications Because of its low DCR (Direct Current Resistance) and high saturation current, the HC1-1R7-R is commonly used in: 1. **Multi-phase Regulators:** Found in PC motherboards and servers to power CPUs. 2. **Voltage Regulator Modules (VRM):** Converting high voltage DC to lower voltage for logic circuits. 3. **DC-DC Converters:** Buck, Boost, and Cuk converters where efficiency is a priority. 4. **Point of Load (POL) Converters:** Providing localized power to FPGAs or ASICs. --- ### 4. Part Number Breakdown Understanding the suffix and prefix: * **HC1:** The series name (High Current, Size 1). * **1R7:** Represents the inductance value. The "R" acts as a decimal point (1.7). * **-R:** Indicates that the part is **RoHS Compliant**. --- ### 5. Performance Advantages * **Low Power Loss:** The 2.5 mΩ DCR ensures very little energy is wasted as heat, even at high current levels. * **High Frequency Efficiency:** Optimized for switching frequencies up to and exceeding 1 MHz. * **Thermal Stability:** Designed to maintain inductance values even as the internal temperature of the device rises.