## Overview of RL1011-221-R The **RL1011-221-R** is a specific model of **Radial Leaded Inductor** (also known as a power choke) manufactured by **Bourns Inc.** This component belongs to the RL1011 series, which is designed for applications requiring high saturation current and durability in a compact footprint. --- ### 1. Technical Specifications Below are the key electrical and physical characteristics of the RL1011-221-R: | Parameter | Value | | :--- | :--- | | **Inductance** | 220 µH | | **Tolerance** | ±10% | | **DC Resistance (DCR)** | 0.35 Ω (Max) | | **Rated Current (I-dc)** | 1.10 A | | **Self-Resonant Frequency** | 2.5 MHz (Min) | | **Core Material** | Ferrite | | **Termination Style** | Radial Leaded (Through-hole) | | **Operating Temperature** | -40°C to +125°C | --- ### 2. Physical Design and Features * **Form Factor:** It features a vertical cylindrical design with two wire leads exiting from the bottom, making it suitable for through-hole mounting on Printed Circuit Boards (PCBs). * **Protection:** The inductor is typically encased in a **polyolefin shrink tube**, which provides mechanical protection and electrical insulation. * **RoHS Compliance:** The "-R" suffix indicates that the part is fully compliant with RoHS (Restriction of Hazardous Substances) standards. --- ### 3. Common Applications Due to its high current rating and inductance value, the RL1011-221-R is commonly used in: 1. **Switching Power Supplies:** Used as an energy storage element or for output filtering. 2. **DC-DC Converters:** Helping to step-up or step-down voltages while minimizing ripple. 3. **EMI/RFI Filtering:** Acting as a low-pass filter to block high-frequency noise in electronic circuits. 4. **Signal Conditioning:** Smoothing out current spikes in consumer electronics and industrial equipment. --- ### 4. Part Number Breakdown Understanding the Bourns nomenclature helps identify variations: * **RL1011:** The Series name (Physical size: approx. 10mm diameter x 11mm height). * **221:** The Inductance Code. The first two digits (22) are significant figures; the third digit (1) is the multiplier ($10^1$). So, $22 \times 10 = 220$ µH. * **R:** Indicates RoHS compliance.