## Overview of the UP1B-4R7-R The **UP1B-4R7-R** is a high-performance power inductor manufactured by **Eaton (formerly Coiltronics/Bussmann)**. It belongs to the Uni-Pac (UP) series, which is specifically designed for surface-mount applications requiring high energy storage and low electromagnetic interference (EMI). --- ### 1. Key Technical Specifications The following table summarizes the electrical and mechanical characteristics of the component: | Parameter | Specification | | :--- | :--- | | **Inductance** | 4.7 µH | | **Tolerance** | ±20% | | **Current Rating (Irms)** | 3.5 Amps (Typical) | | **Saturation Current (Isat)** | 4.4 Amps (Typical) | | **DC Resistance (DCR)** | 0.0242 Ohms (Max) | | **Shielding** | Shielded (Low EMI) | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | 8.9mm x 6.1mm (UP1B Size) | --- ### 2. Core Functional Components The UP1B-4R7-R consists of several critical internal parts: * **Magnetic Core:** Utilizes a ferrite core material. Ferrite is chosen for its high permeability and low eddy current losses, making it efficient for high-frequency switching. * **Winding:** Copper wire wound around the core. The thickness of the wire determines the DC resistance and the current-carrying capacity. * **Shielding:** The "Shielded" construction means the magnetic flux is largely contained within the inductor body. This prevents the component from interfering with nearby sensitive components on the PCB. * **Terminations:** Solder-plated leads designed for Surface Mount Technology (SMT) reflow processes. --- ### 3. Common Applications This specific inductor is widely used in power management circuits, including: 1. **DC-DC Converters:** Buck, Boost, and SEPIC topologies. 2. **Point-of-Load (POL) Regulation:** Used in laptops, servers, and network equipment. 3. **Battery Powered Devices:** Due to its small footprint and high efficiency. 4. **LED Drivers:** Providing stable current for lighting applications. --- ### 4. Part Number Breakdown Understanding the nomenclature helps in identifying variants: * **UP1B**: Series name and physical size (Size 1B). * **4R7**: Inductance value (4.7 microhenries). The "R" acts as a decimal point. * **-R**: RoHS compliant (Lead-free).