2.5G copper, 2500BASE-X fiber
Each JL4201 part lists a 2.5G data rate, a copper port from 10BASE-T upward and a 2500BASE-X optical port. That covers 2.5GBASE-T over twisted pair or a 2.5G optical uplink.
Ethernet Interface Chip products
JL4201 2.5G Ethernet PHY
JL4201 is the fastest device in the range: a single port 2.5G PHY with an SGMII MAC interface and 2500Base-X fibre support, in a QFN48 package at 6 by 6 millimetres. Confirm the host provides SGMII with the bandwidth to match.
Part number search & selector
Find JL4201 2.5G Ethernet PHY part numbers
Filter JL4201 parts by data rate, MAC interface, optical port, temperature, ports, interface voltage, copper port, mode, package and size.
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| Image | Part number | Datasheet | Compare | Downloads | Series | Data Rate | Ports | MAC Interface | V（if） | Copper Port | Optical Port | Mode | Temperature | Package | Size | Sample |
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JL4201-NC | SPEC | JL4201 series | 2.5G | 1 | SGMII | NA | 10 Bsae-T | 2500 Base-X | (H)SGMII-COP | 0~70℃ | QFN48 | 6*6 mm |
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JL4201-NI | SPEC | JL4201 series | 2.5G | 1 | SGMII | NA | 10 Bsae-T | 2500 Base-X | (H)SGMII-COP | -40~85℃ | QFN48 | 6*6 mm |
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By series
Ethernet PHY series by speed and ports
Series are separated by link speed, port count and the MAC interface they present.
Series overview
Specifying the JL4201 2.5G Ethernet PHY
The JL4201 2.5G Ethernet PHY joins the SGMII MAC of a router, access point or gateway SoC to a 2.5G copper port or a 2500BASE-X fiber link. You may also see it as a 2.5GBASE-T PHY, an SGMII PHY or a multi-gig physical layer transceiver. Commercial and industrial grades share one QFN48 package. For gigabit fiber on an RGMII host, see the JL2201 series.
SGMII host, (H)SGMII mode
The MAC interface is SGMII and the mode column reads (H)SGMII-COP. Standard SGMII stops at 1G, so confirm in the datasheet which host mode carries 2.5G and that your SoC supports it.
NC or NI grade
JL4201-NC is rated 0 °C to 70 °C for home and office products; JL4201-NI covers −40 °C to +85 °C for outdoor access points and industrial gateways.
QFN48 and 2.5G magnetics
The QFN48 package measures 6 × 6 mm. On the copper side, VOOHU also offers 2.5G and 5G Ethernet transformers to evaluate on your board.
Applications
Where the JL4201 2.5G Ethernet PHY fits
JL4201 targets ports where a 1G link has become the bottleneck.
Access points and mesh routers
Wi-Fi 6 and Wi-Fi 7 access points can pass more than 1G over the air, so their wired uplink needs 2.5G. JL4201-NI suits ceiling and outdoor units at −40 °C to +85 °C.
Home gateways and 2.5G LAN ports
Fiber and cable gateways add a 2.5G LAN or WAN port so multi-gig internet plans reach the home network. JL4201-NC covers these indoor products at 0 °C to 70 °C.
2500BASE-X fiber uplinks
Industrial and enterprise switches with an SFP-style uplink can use the 2500BASE-X side of this Ethernet transceiver to reach the next switch over fiber.
Documents
JL4201 2.5G Ethernet PHY datasheets
Search by part number to open the JL4201 datasheet, then check the SGMII mode, 2500BASE-X setup and QFN48 outline before layout.
Showing representative available file sets. Search to find a specific SKU.
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- PCB footprints listed
VOOHU’s published product content is reviewed by its engineering team. Specifications, downloads and technical support information are tied to specific part numbers, so you can verify them before requesting samples or a quotation.
Sourcing
Buying the JL4201 2.5G Ethernet PHY from VOOHU
VOOHU is an authorized JLSemi distributor for this series. Each part number has a PDF datasheet covering SGMII settings, 2500BASE-X configuration and the QFN48 drawing.
Discuss a new design
Contact FAE for a replacement assessment.
Already have a part number? Request samples or a quote.
Samples and quotes
Samples are available for evaluation, and selected parts are free of charge. Our FAE team will be glad to confirm the options for your project. For a quotation, share the part number, quantity and target date, and we will confirm availability.
Upgrading from a gigabit PHY
Send the part number and datasheet of the PHY you use today, whether 1G or 2.5G. Our FAE team compares SGMII mode, line side and package, reviews register and layout differences, and suggests candidates to validate with samples before production.
Quality and company
VOOHU is ISO 9001 and ISO 14001 certified. Since 2018 VOOHU has supplied more than 1,500 customers, including 150+ listed companies.
FAQ
JL4201 2.5G Ethernet PHY: common questions
Authorized supply, lower copper speeds and the choice against JL2101.
What is JL4201 for?
Multi-gigabit links at 2.5G, either as an access port or an uplink. It presents SGMII on the MAC side and supports 2500Base-X on fibre. Confirm your host controller provides SGMII and can sustain 2.5G before selecting it, because the interface is not convertible.
How does SGMII differ from RGMII?
SGMII is a serial interface using few signals at high rate; RGMII is a parallel interface using more signals at lower rate. They are electrically different and cannot be connected to one another. The PHY has to match whatever the host controller provides, so start from that.
What does 2.5G demand on the copper side?
Tighter control of the differential pairs and magnetics rated for multi-gigabit operation. A LAN transformer specified only for gigabit may not hold signal integrity at 2.5G. Choose magnetics rated for the speed and verify link quality and emissions on the real board.
How do I use 2500Base-X?
Configure the fibre mode as described in the datasheet reference design and pair it with a suitable optical module. If your design needs both copper and fibre, confirm which operating arrangement the device supports rather than assuming both run concurrently.
How do I request samples or a quote?
With a complete part number, send the part number, quantity, delivery region and the date you need it. If you are still selecting, send the host controller and its SGMII capability, whether you need fibre, and the operating temperature range.
Is the JL4201 2.5G Ethernet PHY sold through an authorized channel?
Yes. VOOHU is an authorized JLSemi distributor for the NC and NI grades, and the team that quotes the chip can also review your SGMII connection and 2.5G copper layout.
Can JL4201 link with older 1G or 100M equipment?
The copper port is listed from 10BASE-T, so lower speeds sit within its range. Confirm the supported speeds and auto-negotiation behavior in the datasheet before you rely on them.
Should I use JL4201 or the JL2101 Gigabit Ethernet PHY for a copper port?
Start from the host. JL2101 takes RGMII and stops at 1G in a QFN40 package; this chip needs SGMII and reaches 2.5G, with a 2500BASE-X fiber option in QFN48. If 1G is enough and the SoC offers RGMII, JL2101 is the natural fit.
Engineer support
JL4201 2.5G Ethernet PHY samples and support
Send the candidate part number and the condition you need reviewed. Sample support can be added after the selection is clear; commercial questions may be discussed in the same engineering conversation.
- 1Selected part numbers
- 2Engineering review
- 3Sample request
- 4Commercial discussion
For a replacement review
- Original part and datasheet
Include the document revision
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To help prioritize samples and evaluation
- Target review date
When you need candidates and a comparison of differences
Engineering review identifies candidate parts and explains the differences.
For samples and a quotation
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Prototyping / pilot build / production
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Specify sample and production timing separately
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Samples are free of charge. Sample quantity and lead time depend on the part number and project stage. Sales will respond on business days.
