The **CMH322522-R39ML** is a surface-mount (SMD) wire-wound chip inductor. It is commonly used in high-frequency circuits for noise filtering, signal shaping, and impedance matching. Below is a detailed breakdown of its specifications and electronic characteristics. ### 1. Part Number Deciphering The alphanumeric code provides specific details about the component's physical and electrical properties: | Segment | Meaning | Description | | :--- | :--- | :--- | | **CMH** | Series Code | High-frequency wire-wound chip inductor series. | | **322522** | Dimensions | Metric size: 3.2mm x 2.5mm x 2.2mm (EIA 1210). | | **R39** | Inductance | **0.39 µH** (R denotes the decimal point). | | **M** | Tolerance | **±20%** (Standard tolerance for this series). | | **L** | Packaging | Typically denotes Tape & Reel packaging. | --- ### 2. Technical Specifications These values represent the typical performance metrics for this specific part: | Parameter | Value | | :--- | :--- | | **Inductance** | 0.39 µH | | **Tolerance** | ±20% | | **DC Resistance (DCR)** | ~0.35 Ω (Max) | | **Rated Current** | ~450 mA | | **Self-Resonant Frequency (SRF)** | > 250 MHz | | **Quality Factor (Q)** | Min 30 (at 25.2 MHz) | | **Operating Temperature** | -40°C to +105°C | --- ### 3. Key Electronic Characteristics * **Wire-Wound Construction:** Unlike multilayer inductors, the wire-wound design allows for a higher **Q factor** (efficiency) and lower DC resistance, making it suitable for power lines and RF applications. * **High Resonance:** The high SRF ensures that the component maintains its inductive properties even at high frequencies before becoming capacitive. * **Physical Durability:** The 1210 (3225) package is large enough to handle moderate current while remaining small enough for automated pick-and-place PCB assembly. ### 4. Common Applications * **RF Modules:** Used in wireless communication devices for matching circuits. * **EMI Suppression:** Filtering high-frequency noise in power supply lines (DC-DC converters). * **Signal Processing:** Frequency selection in telecommunication equipment. ---