The **TCDA1090-R39M** is a high-performance, surface-mount (SMD) power inductor commonly used in DC-DC converter applications and power management modules. ### 1. Key Technical Specifications Below are the primary electrical and physical characteristics of the TCDA1090 series: | Parameter | Specification | | :--- | :--- | | **Inductance** | 0.39 µH (indicated by "R39") | | **Tolerance** | ±20% (indicated by "M") | | **Dimensions** | 10.0 x 9.0 mm (approximate footprint) | | **DCR (Direct Current Resistance)** | Very Low (typically < 1.0 mΩ) | | **Saturation Current ($I_{sat}$)** | High (designed for high-current spikes) | | **Operating Temperature** | -40°C to +125°C (standard automotive/industrial grade) | --- ### 2. Composition and Design * **Core Material:** Usually utilizes a metal alloy powder core. This provides high saturation flux density and prevents "hard" saturation (where inductance drops off instantly). * **Shielding:** It is a **magnetically shielded** construction, which minimizes Electromagnetic Interference (EMI) with surrounding components on the PCB. * **Terminations:** Features robust lead-frame or bottom-surface electrodes for stable soldering in high-vibration environments. --- ### 3. Part Number Breakdown Understanding the nomenclature helps in identifying variants: 1. **TCDA**: Series identifier (Metal Alloy Power Inductor). 2. **1090**: Physical size (roughly 10mm length and 9.0mm width). 3. **R39**: Inductance value. "R" acts as a decimal point, meaning **0.39 µH**. 4. **M**: Tolerance code (M = ±20%). --- ### 4. Common Applications Due to its high current handling and low profile, this part is found in: * **Voltage Regulator Modules (VRMs):** Powering CPUs and GPUs in servers or laptops. * **Automotive Electronics:** Infotainment systems and ADAS sensors. * **DC-DC Converters:** High-efficiency buck or boost converters. * **Battery Powered Devices:** Where low DCR is critical to preserving battery life. --- ### 5. Implementation Example In a standard Buck Converter circuit, the inductor is placed at the output stage to smooth the current. ```spice * Simple representation of TCDA1090 in a buck stage VIN 1 0 DC 12V SW1 1 2 ... (Switching Controller) L1 2 3 0.39uH ; The TCDA1090-R39M C1 3 0 100uF ; Output Capacitor RLOAD 3 0 1 ; Load ```