## Overview of SDR1045-101K The **SDR1045-101K** is a high-power, surface-mount device (SMD) inductor manufactured by Bourns. It is part of the SDR1045 series, known for its non-shielded construction and high current handling capabilities. ### Technical Specifications | Parameter | Value | | :--- | :--- | | **Inductance** | 100 µH | | **Tolerance** | ±10% (Indicated by 'K') | | **DC Resistance (DCR)** | 0.25 Ω Max | | **Saturation Current (Isat)** | 1.10 A | | **Heating Current (Irms)** | 1.00 A | | **Package / Case** | SMD (10.1 x 10.1 x 4.5 mm) | | **Operating Temperature** | -40°C to +125°C | --- ### Component Breakdown #### 1. Part Number Deciphering * **SDR**: Series name (Surface Mount Power Inductor). * **1045**: Physical dimensions (approx. 10mm diameter, 4.5mm height). * **101**: Inductance code. The first two digits are significant figures, and the third is the multiplier ($10 \times 10^1 = 100$). * **K**: Tolerance code (K = ±10%). #### 2. Physical Construction The device consists of a **ferrite drum core** wound with copper wire. Because it is "non-shielded," the magnetic field is not contained within the component. This allows for higher saturation currents in a smaller footprint but requires careful placement on a PCB to avoid Electromagnetic Interference (EMI) with neighboring components. #### 3. Core Material It typically uses a Ferrite core, which provides high permeability and low eddy current losses, making it efficient for power conversion applications. --- ### Common Applications * **DC-DC Converters:** Used as energy storage elements in buck, boost, or SEPIC converters. * **Power Supplies:** Found in laptops, telecommunications equipment, and consumer electronics. * **Input/Output Filters:** Used to smooth out voltage ripples and reduce noise in power lines. * **LCD Displays:** Often used in the backlight driving circuitry. --- ### Comparison with Shielded Alternatives | Feature | SDR1045 (Non-Shielded) | SRR1045 (Shielded) | | :--- | :--- | :--- | | **Cost** | Lower | Higher | | **EMI Profile** | High radiation | Low radiation | | **Saturation Current** | Generally higher for size | Slightly lower | | **Best For** | Cost-sensitive power apps | Noise-sensitive signal apps |