The **AMPLH4020S-R33M** is a high-performance, shielded power inductor typically used in DC-DC converter applications. It belongs to a class of surface-mount devices (SMD) designed for high current density and low core loss. --- ### 1. Part Number Breakdown Understanding the nomenclature helps identify the physical and electrical characteristics of the component: | Segment | Meaning | Specification | | :--- | :--- | :--- | | **AMPLH** | Series Name | High-current, low-profile molded power inductor | | **4020** | Case Size | ~4.0mm x 4.0mm x 2.0mm | | **S** | Standard/Shielding | Shielded construction (low EMI) | | **R33** | Inductance Value | 0.33 µH (Microhenries) | | **M** | Tolerance | ±20% | --- ### 2. Technical Specifications While exact values can vary slightly by manufacturer (e.g., Cyntec, Abracon, or others using this standard footprint), the general specifications for an R33M in this size are: * **Inductance:** 0.33 µH * **DC Resistance (DCR):** Typically very low (approx. 3.0mΩ - 5.0mΩ) to minimize power dissipation. * **Saturation Current ($I_{sat}$):** High, usually ranging from 12A to 18A (the point where inductance drops by 30%). * **Rated Current ($I_{rms}$):** Based on temperature rise, typically around 10A to 14A. * **Operating Temperature:** -40°C to +125°C (including self-heating). --- ### 3. Key Features & Construction 1. **Molded Structure:** The coil is embedded in a metal alloy powder. This "molded" design provides superior magnetic shielding compared to traditional wire-wound ferrites. 2. **Low EMI:** Because the magnetic flux is contained within the molded body, it produces very little electromagnetic interference (EMI), making it ideal for densely packed circuit boards. 3. **Soft Saturation:** Unlike ferrite inductors that lose inductance sharply when current limits are exceeded, these metal powder inductors exhibit a "soft" saturation curve. 4. **High Frequency:** Optimized for high-frequency switching regulators (up to 5MHz). --- ### 4. Common Applications This part is commonly found in power management stages for: * **Laptops and Tablets:** VRM (Voltage Regulator Module) for CPUs and GPUs. * **Smartphone Circuitry:** High-efficiency DC-DC buck converters. * **SSD Power Supplies:** Providing stable voltage in compact form factors. * **Distributed Power Systems:** Point-of-Load (POL) converters. ---