The **CTMC1812-R15M** is a high-frequency, surface-mount (SMD) wire-wound chip inductor. It is commonly used in telecommunications, automotive electronics, and signal filtering applications. Below is the detailed breakdown of its electronic specifications and characteristics. --- ### 1. General Specifications The part number follows a standardized naming convention that describes its physical size and electrical value. | Parameter | Specification | | :--- | :--- | | **Component Type** | Wire-wound Chip Inductor | | **Inductance** | 0.15 µH | | **Tolerance** | ±20% (indicated by the 'M') | | **Case Size** | 1812 (4.5mm x 3.2mm) | | **Mounting Type** | Surface Mount (SMD) | --- ### 2. Electrical Characteristics These values define how the inductor performs under load and at specific frequencies. | Feature | Value | Description | | :--- | :--- | :--- | | **Q-Factor (Min)** | 30 | Quality factor at 25.2 MHz. | | **Self-Resonant Frequency (SRF)** | 450 MHz | The point where the part becomes capacitive. | | **DC Resistance (DCR)** | 0.44 Ω (Max) | The internal resistance of the copper winding. | | **Rated Current (Idc)** | 450 mA | The maximum current it can handle before overheating. | --- ### 3. Part Number Breakdown To understand the manufacturer's logic (Central Technologies), the code is deciphered as follows: * **CTMC**: Series prefix (Molded Chip Inductor). * **1812**: Dimensions (Length: 0.18" / Width: 0.12"). * **R15**: The inductance value. "R" acts as a decimal point ($0.15$ microhenries). * **M**: Tolerance code (J = 5%, K = 10%, **M = 20%**). --- ### 4. Key Applications * **RF Tuning:** Used in resonant circuits for high-frequency communication. * **Signal Decoupling:** Preventing high-frequency noise from passing through power lines. * **Filters:** Integral in Low Pass and Band Pass filters for telecommunications. * **Automotive:** Often used in infotainment and body control modules due to its robust molded construction. --- ### 5. Construction and Material The **CTMC1812** series typically features: 1. **Core Material:** Ferrite or Ceramic (depending on the specific frequency range). 2. **Encapsulation:** Molded epoxy resin, which provides excellent mechanical strength and resistance to moisture/chemicals. 3. **Terminations:** Solder-plated copper or silver, designed for standard reflow soldering processes.