The **SRP1040-R15M** is a high-current, shielded power inductor manufactured by Bourns. It is part of the SRP1040 series, widely used in DC/DC converters and power supplies for high-reliability applications. --- ## 1. Technical Specifications The part number follows a specific nomenclature that defines its physical and electrical characteristics. | Parameter | Value | Description | | :--- | :--- | :--- | | **Inductance** | 0.15 µH | The nominal inductance at 100 kHz. | | **Tolerance** | ±20% | Indicated by the "M" suffix. | | **Irms (Heating Current)** | 35.0 A | Current that causes a 40°C temperature rise. | | **Isat (Saturation Current)** | 60.0 A | Current at which inductance drops by 20%. | | **DCR (DC Resistance)** | 1.3 mΩ (Max) | Internal resistance of the wire. | | **Operating Temp** | -40°C to +125°C | Thermal range including self-heating. | --- ## 2. Key Physical Features ### Construction * **Carbonyl Iron Powder Core:** The inductor uses a pressed metal alloy powder core. This provides "soft" saturation characteristics, meaning the inductance doesn't drop off instantly when peak current is reached. * **Shielded Design:** The molded construction provides magnetic shielding, which minimizes Electromagnetic Interference (EMI) with surrounding components. * **Flat Wire Technology:** It often utilizes flat copper wire to reduce DC resistance (DCR) and improve efficiency compared to round wire. ### Package Dimensions (1040 Series) The "1040" designation refers to the physical footprint: * **Length:** ~11.5 mm * **Width:** ~10.0 mm * **Height:** ~4.0 mm --- ## 3. Common Applications Due to its very low inductance (0.15 µH) and extremely high current handling (60A Saturation), this part is typically used in: 1. **Voltage Regulator Modules (VRM):** Specifically for CPUs and GPUs where low voltage and high current are required. 2. **High-frequency DC/DC Converters:** Ideally suited for high-speed switching power supplies. 3. **Distributed Power Systems:** Used in telecommunications and industrial servers. --- ## 4. Part Number Breakdown `SRP 1040 - R15 M` * **SRP:** Product Series (High Current Shielded Inductor). * **1040:** Size Code (10mm x 4mm). * **R15:** Inductance Value (R denotes decimal, so 0.15 µH). * **M:** Tolerance (±20%).