FAQ
Frequently Asked Questions
Is a chip LAN transformer a PHY IC?
No. A chip LAN transformer in this catalog is a passive magnetic component. The PHY IC handles Ethernet physical-layer transmission and reception. They are not interchangeable. Check the part number, schematic and component function so that a transformer search does not turn into an Ethernet-controller IC selection.
How does a chip LAN transformer differ from a common mode choke?
A transformer couples signals and provides the isolation performance specified for its construction. A common mode choke primarily suppresses common mode noise. A choke alone is not a complete Ethernet isolation transformer. Even when both appear under CHIP LAN, confirm their separate BOM roles and surrounding circuits rather than assuming all functions are integrated in one package.
How do I select a chip LAN transformer?
Start with the PHY model, target data rate, PoE requirements and available PCB space. Compare candidate parts for OCL, bias conditions, loss specifications and pin assignments. For Gigabit, 2.5G, 5G or 10G designs, select a version explicitly covered by the datasheet and validate samples in the intended circuit.
Can CHIP LAN support PoE, PoE+ or PoE++?
There is no single answer for the whole category. The catalog includes non-PoE parts and parts intended for PoE applications. Check the exact part, power standard, current definition and thermal conditions. PoE+ and PoE++ can describe your project requirements, but they are not per-transformer power guarantees. The milliamp bias used in an OCL test is not a power-delivery current rating.
Can a chip-format solution directly replace a conventional LAN transformer module?
Matching speed or appearance does not establish a drop-in replacement. A conventional module may contain multiple transformers and common mode chokes. A discrete magnetics design also requires review of companion components, pins, routing, isolation and PoE conditions. Send the current part or schematic so FAE can identify candidates and explain differences before sample validation.
Is there a universal circuit for capacitively coupled CHIP LAN?
No universal circuit should be assumed. Review the coupling capacitors, companion magnetics, PHY interface and protection network against the specific reference design. A capacitor voltage rating does not establish system isolation. This page does not prescribe a capacitor value, component placement or isolation threshold for every part. Share your PHY and application conditions for an appropriate evaluation path.
What information is needed for samples, pricing and lead time?
If you have a part number, share it with the quantity, project stage, destination and requested dispatch date. Pricing depends on the part and quantity; sales will confirm availability and lead time. If no part has been selected, start with the application and target speed. For a replacement request, attach the existing-part documentation—you do not need to complete the comparison yourself first.
How should I use the datasheet, PCB footprint and reflow information?
Download files for the same part number and check their revisions. Use the datasheet for electrical conditions and winding connections, the dimension drawing and footprint for pads and orientation, and the relevant reflow profile for the process window. If files are missing or revisions conflict, ask an engineer before substituting documentation from another family.
