## Technical Overview of DR124-121-R The **DR124-121-R** is a high-power, shielded surface-mount (SMD) inductor manufactured by Eaton (formerly Bussmann/Coiltronics). It is part of the DR series, which is specifically designed for high-density applications requiring low electromagnetic interference (EMI). --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Inductance** | 120 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 0.354 Ω (Typical) | | **Saturation Current ($I_{sat}$)** | 1.16 Amperes | | **RMS Current ($I_{rms}$)** | 1.05 Amperes | | **Operating Temperature** | -40°C to +125°C | | **Dimensions** | 12.5mm x 12.5mm x 4.5mm | --- ### 2. Physical Construction and Features * **Shielded Design:** The core is ferrite-shielded, which significantly reduces EMI. This makes it ideal for use near sensitive components like microcontrollers or wireless modules. * **Drum Core Technology:** It utilizes a high-power density drum core, which allows for a small footprint while maintaining high energy storage capabilities. * **SMD Package:** Designed for automated pick-and-place assembly with a flat top for vacuum nozzles. * **Lead-Free/RoHS:** The "-R" suffix indicates that the part is fully RoHS compliant. --- ### 3. Common Applications The DR124-121-R is commonly found in power management circuits, specifically: 1. **Buck/Boost Converters:** Used as the energy storage element in DC-DC converters. 2. **Noise Filtering:** Acting as a choke in power lines to smooth out voltage ripples. 3. **LED Drivers:** Providing stable current for lighting systems. 4. **Computer Peripherals:** Used in laptops, servers, and networking equipment. --- ### 4. Interpretation of the Part Number ```text DR 124 - 121 - R | | | | | | | └── RoHS Compliant | | └────── Inductance Code (12 * 10^1 = 120 µH) | └──────────── Physical Size (approx. 12mm wide, 4mm high) └──────────────── Series Name (Drum Core Shielded) ```