The **DR74-151-R** is a high-performance power inductor manufactured by **Eaton (formerly Bussmann/Coiltronics)**. It is part of the DR series, which is known for its shielded drum core construction and high energy density. --- ### 1. Technical Specifications The part number "DR74-151-R" encodes specific technical data: | Parameter | Value | Details | | :--- | :--- | :--- | | **Inductance** | 150 µH | The "151" indicates 15 and 1 zero (150) | | **Tolerance** | ±20% | Standard for power inductors | | **DC Resistance (DCR)** | 0.506 Ω (Typical) | Resistance of the internal wire | | **Rated Current (Irms)** | 0.81 Amps | Current that causes a 40°C temperature rise | | **Saturation Current (Isat)** | 0.94 Amps | Current where inductance drops by 25% | | **Operating Temp** | -40°C to +125°C | Suitable for industrial applications | | **Package Size** | 7.6 x 7.6 x 4.35 mm | Surface Mount (SMD) | --- ### 2. Key Internal Components The DR74 series is designed with specific materials to optimize performance: * **Ferrite Drum Core:** Provides a high magnetic permeability, allowing for high inductance in a small footprint. * **Magnet Wire:** Copper windings around the core that carry the electrical current. * **Magnetic Shielding:** The "DR" series is shielded, meaning the magnetic field is largely contained. This reduces **Electromagnetic Interference (EMI)** with nearby components on the PCB. * **Epoxy/Resin:** Used to secure the shield to the core and protect the windings from environmental factors. --- ### 3. Common Applications This specific inductor (150 µH) is typically found in power management circuits: 1. **DC-DC Converters:** Used in Buck (step-down) or Boost (step-up) converters to store energy. 2. **Output Filters:** Smoothing out ripple current in switching power supplies. 3. **LED Drivers:** Providing stable current for high-brightness LEDs. 4. **Battery Powered Equipment:** Used in portable electronics where space and efficiency are critical. --- ### 4. Part Number Breakdown The nomenclature follows a specific logic: * **DR:** Series name (Dual Winding/Shielded Inductor). * **74:** Size code (approx. 7.6mm width, 4.35mm height). * **151:** Inductance value (15 followed by one 0 = 150 µH). * **R:** RoHS compliant (Lead-free).