## Overview of the SD20-680-R The **SD20-680-R** is a high-performance, surface-mount (SMD) power inductor part of the **SD20 Series** manufactured by **Eaton (formerly Cooper Bussmann)**. These inductors are designed for applications requiring high power density and a low profile. --- ### 1. Key Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 68.0 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | 1.157 Ω (Typical) | | **Rated Current (Irms)** | 0.53 Amps | | **Saturation Current (Isat)** | 0.50 Amps | | **Operating Temperature** | -40°C to +125°C | | **Core Material** | Ferrite | --- ### 2. Component Composition and Design The "Electronic Parts" aspect of this component involves several engineering features: * **Shielded Construction:** The inductor is magnetically shielded. This is critical for minimizing Electromagnetic Interference (EMI), ensuring that the magnetic field generated by the coil does not interfere with nearby sensitive components on the PCB. * **Ferrite Core:** It utilizes a ferrite drum core which provides high permeability and low core losses at high frequencies. * **Surface Mount Technology (SMT):** The "SD20" designation refers to the physical footprint size (approximately 5.2mm x 5.2mm x 2.0mm). The flat top surface is optimized for automated "pick and place" assembly. * **RoHS Compliant:** The "-R" suffix indicates that the part is lead-free and complies with RoHS standards. --- ### 3. Functional Application The SD20-680-R is primarily used in **Power Management** circuits. Its role is to store energy in a magnetic field and smooth out current fluctuations. Common use cases include: 1. **Buck/Boost Converters:** Used in DC-to-DC converters to step voltages up or down efficiently. 2. **LED Drivers:** Provides constant current for lighting applications. 3. **Noise Filtering:** Acts as a low-pass filter to block high-frequency noise in power supply lines. 4. **Battery Powered Devices:** Due to its small 2.0mm height, it is ideal for mobile phones, tablets, and handheld sensors. --- ### 4. Circuit Symbol and Behavior In a schematic, the SD20-680-R is represented by the standard inductor symbol. Its behavior is governed by the formula: `V = L * (di/dt)` Where: * **V** is the voltage across the inductor. * **L** is 68.0 µH. * **di/dt** is the rate of change of current.