The **CTMC1812-R12M** is a high-frequency, surface-mount (SMD) wire-wound chip inductor. It is commonly used in RF circuits, power supplies, and signal filtering applications. --- ### ## Technical Specifications Below are the primary electrical and physical characteristics of the CTMC1812-R12M: | Parameter | Value | | :--- | :--- | | **Inductance** | 0.12 µH (R12) | | **Tolerance** | ±20% (M) | | **Test Frequency** | 25.2 MHz | | **DC Resistance (DCR) Max** | 0.22 Ω | | **Rated Current (I-dc)** | 550 mA | | **Self-Resonant Frequency (SRF)** | 500 MHz | | **Package / Case** | 1812 (4532 Metric) | | **Operating Temperature** | -40°C to +125°C | --- ### ## Key Features * **Wire-Wound Construction:** Provides higher Q-factors and higher current handling capabilities compared to multilayer inductors. * **Molded Encapsulation:** The "CTMC" prefix often refers to a molded chip inductor, which offers excellent mechanical strength and resistance to moisture and environmental stress. * **1812 Form Factor:** A standard surface-mount size (4.5mm x 3.2mm), making it compatible with automated pick-and-place assembly. ### ## Part Number Breakdown Understanding the nomenclature helps in identifying variants: 1. **CTMC:** Series name (Ceramic/Molded Chip Inductor). 2. **1812:** Physical dimensions (0.18 x 0.12 inches). 3. **R12:** Inductance value ($0.12 \mu H$). The "R" acts as a decimal point. 4. **M:** Tolerance code ($M = \pm 20\%$). ### ## Common Applications * **RF Tuning:** Used in high-frequency communication equipment. * **Decoupling:** Filtering high-frequency noise out of power lines. * **Signal Processing:** Used in filters and oscillators where a specific inductance value is required to maintain resonance. ---