FIND BY PROBLEM · MATCHING
PHY Selected. Which Transformer and RJ45 Fit?
Share your PHY and application conditions. Our engineers return candidate combinations, operating conditions, and document versions. Unreviewed combinations are clearly marked "Engineering review required".
WHEN TO USE
Situations You May Be Facing
Not the right page if:
- You want to replace an existing transformer → Find a Replacement
- The Ethernet port is already failing → Troubleshooting
- You only need a compact part → Filter by Size
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PHY or Switch Chip Already Selected
The main chip is decided and you need a matching LAN transformer and RJ45, preferably a reviewed reference combination rather than filtering parts yourself.
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Multi-Port or High-Speed Design
2.5G / 5G / 10G or multi-port designs need tight return loss, crosstalk, and port consistency, so test conditions at the target speed must be confirmed.
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PoE Is Involved
PSE or PD role and power class (af / at / bt) directly affect the transformer center tap and RJ45 choice and must be checked together.
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Space or Mounting Constraints
Board height, panel cutout, SMT or through-hole requirements call for a suitable package that still meets the electrical match.
MATCHING PROCESS
Get a Matched Combination in Three Steps
First reply within 1 business day. If there is no reviewed reference combination for your PHY yet, we move it to engineering review and tell you how long it will take. Enter "Not sure" for any unknown parameter.
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You · About 5 minutes
Share PHY and Application
Tell us the chip, speed, port count, whether PoE is used, and the operating environment. Enter "Not sure" for anything unclear.
- PHY / Switch part
- Speed & port count
- PoE role & power
- Temp · Space · Mounting
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VOOHU · First reply in 1 business day
Engineer Matching
Reviewed reference designs come first. Otherwise we match by the dimensions below and mark items for you to confirm or for engineering review.
- Reference design library
- Parameter matching
- Operating conditions
- Open items
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You · Confirm & verify
Get Combinations and Documents
You receive transformer + RJ45 combinations, operating conditions, document versions, and suggested verification steps. Request samples when needed.
- 1–3 combinations
- Operating conditions
- Document versions
- Sample request
MATCHING DIMENSIONS
How We Match
Each combination is labeled with one of three statuses:Reviewed reference design / Parameter match (with conditions) / Engineering review required
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Speed & Interface
10/100M, 1G, 2.5G/5G/10G and MDI interface type. We confirm the datasheet test band covers the target speed.
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Ports & Layout
Single, dual, or stacked multi-port, with crosstalk and consistency requirements. RJ45 and transformer port counts must match.
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PoE Role & Power
PSE / PD and af / at / bt power class, which set the center tap current rating and the RJ45 current rating.
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Electrical Match
Turns ratio, OCL, insertion loss, return loss, CMRR, and isolation voltage against the PHY datasheet recommendations.
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Temperature & Environment
Industrial or commercial temperature range, protection rating, salt spray or vibration requirements.
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Package & Mounting
Height, footprint, SMT or through-hole, shielding or LEDs, and PCB layout and land pattern constraints.
RELATED PRODUCTS & RESOURCES
Before You Select
Matching Product Lines
- LAN Transformers10/100M to 10G · Single and multi-portView →
- RJ45 ConnectorsStandard / PoE / LED and shieldedView →
- Ethernet PHYSelected together with magneticsView →
These are related categories. Confirmed parts for your PHY come with the reply, including document versions and operating conditions.
Downloads
Download Center →Published Reference Designs
- Ethernet Interface and Magnetics Reference DesignEthernet Solution · OngoingRead →
- Ethernet Circuit Design GuideTechnical ArticleRead →
Reference designs apply to specific PHYs and test conditions and may not apply to your application.
Share PHY Details to Get a Combination
Click to open the inquiry form and describe your requirements in detail. An engineer replies within 1 business day.
Weekdays 8:30–18:00 (UTC+8) · +86 400-1048-018
