Choosing an Alternate Inductor Using Octopart: Step-by-Step Guide

Finding the right inductor for a switching regulator can be a challenge, especially when availability changes or your design requirements evolve. In the second part of our Octopart video series, we dive into how to select an alternate inductor for a battery charger IC with an integrated switching regulator.

In case you missed Part 1, we explored how to find alternate ceramic capacitors using Octopart’s filtering system. This time, we’re applying similar techniques to inductors, focusing on real-world design parameters and practical selection tips.

The Design Context: Micro Quadcopter PCB

We’re working with a micro quadcopter control PCB, which includes a battery charger and system power management IC - the Texas Instruments BQ24192. This chip integrates a buck-boost converter that requires an external inductor.

The inductor used in the original design is a 2.2µH, shielded SMD component, chosen for:

• High current capacity (≥4.5 A)
• Compact footprint (≤5x5 mm)
• Low DC resistance (DCR)
• High self-resonant frequency
• Lifecycle and availability status

When your design constraints change - for example, due to higher load currents, stock issues, or board layout - having a quick and reliable way to find a suitable alternate is crucial.

Key Considerations for Inductor Selection

Before we jump into Octopart, it’s essential to understand what to look for in a replacement:

• Inductance Value (L): Match the original (2.2 µH), unless a design change requires otherwise.
• Current Rating: Your inductor must handle both average and peak currents without saturation.
• DCR (DC Resistance): Lower values improve efficiency.
• Shielding: Helps with EMI control, highly recommended for switching regulators.
• Package Size: Must fit your PCB layout.
• Lifecycle Status: Avoid obsolete or NRND parts.
• Other Specs: Tolerance, self-resonant frequency, thermal performance.

Want to dig deeper into how inductors work in switching regulators? Check out the Inductor Selection Guide.

Using Octopart to Find an Alternate Inductor

Now that you know your parameters, here’s how to use Octopart to find an alternate part.

1. Start from Octopart's Inductor Category

• Go to Electronic Parts → Passive Components → Inductors → Fixed Inductors. This gives you access to a vast range of inductors from multiple manufacturers and distributors.

2. Apply Smart Filters

Use Octopart’s powerful filter tools:

• Inductance: 2.2 µH
• Current Rating: ≥4.5 A (we used 5.0 A and 5.5 A as examples)
• Shielded: Yes
• Package Size (optional): ≤5x5 mm

• Add New Filters: You can also click “Add New Filter” to refine for DCR, lifecycle status, RoHS, and more.

3. Compare Results Efficiently

Switch to the Part Specifications tab to:

• Compare parts side-by-side
• Sort by DCR, size, price, or stock
• Check lifecycle status and number of sellers
• Download datasheets, CAD models, and inventory insights

In our case, we found a 2.2 µH inductor with 5.5 A current rating, low DCR (~35 mΩ), and a small footprint - all from a trusted supplier with good stock availability.

Bringing the Part Into Your Design

Once you’ve identified a part:

• Use Manufacturer Part Search in Altium Designer or your preferred ECAD tool.
• Alternatively, download CAD models from Octopart (symbol, footprint, and 3D model).
• Place the part into your design and verify your layout and simulation specs.

Wrap-Up: Fast, Reliable Inductor Sourcing with Octopart

As you’ve seen in this walkthrough, Octopart makes it incredibly efficient to source inductors, even when dealing with complex specs like switching regulators.

Whether you’re optimizing, replacing, or future-proofing your designs, Octopart’s tools give you access to up-to-date stock data, in-depth filters, and essential design resources all in one place.

Learn how to find alternate field-effect transistors in Part 3 of our Octopart video series—watch it here!

Try Octopart today and keep your next project on track—with smarter sourcing from day one.