## Overview of the UP2C-221-R The **UP2C-221-R** is a high-performance, shielded power inductor designed by **Eaton (formerly Bussmann/Coiltronics)**. It belongs to the **Uni-Pac (UP)** series, which is characterized by its drum core construction and magnetic shielding. --- ### Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 220 µH | | **Tolerance** | ±20% | | **Inductance Code** | 221 (22 followed by one zero) | | **DC Resistance (DCR)** | 0.540 Ω (Maximum) | | **RMS Current ($I_{rms}$)** | 0.81 Amps | | **Peak Current ($I_{sat}$)** | 1.0 Amps | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | Surface Mount (SMT) | --- ### Key Features and Construction 1. **Magnetic Shielding:** The inductor is shielded, which minimizes Electromagnetic Interference (EMI). This makes it suitable for densely packed circuit boards where noise sensitivity is a concern. 2. **Ferrite Core:** It uses a ferrite drum core that provides high efficiency and low core losses at high frequencies. 3. **Low Profile:** The "2C" designation refers to a specific physical size (approx. 12.9mm x 9.4mm x 5.0mm), providing a balance between power handling and board space. 4. **RoHS Compliant:** The "-R" suffix indicates that the part is lead-free and meets RoHS environmental standards. --- ### Common Applications The UP2C-221-R is typically used in power management circuits where stable inductance and noise suppression are required: * **DC-DC Converters:** Buck, Boost, and SEPIC topologies. * **LED Drivers:** Providing constant current for lighting applications. * **Filtering:** Acting as a low-pass filter to smooth out ripples in power supplies. * **Computer Peripherals:** Used in laptops and servers for localized voltage regulation. --- ### Design Considerations When integrating this part into a circuit, consider the following: * **Self-Resonant Frequency (SRF):** Ensure your operating frequency is well below the SRF to maintain inductive behavior. * **Thermal Management:** The $I_{rms}$ rating is based on a specific temperature rise (usually 40°C). Exceeding this current can lead to overheating. * **Saturation:** If the peak current exceeds $I_{sat}$, the inductance will drop significantly, potentially causing circuit instability.