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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".

Request a Matching Review → See the Matching Process

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

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.
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.
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.
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.

1
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
2
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
3
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

Speed & Interface

10/100M, 1G, 2.5G/5G/10G and MDI interface type. We confirm the datasheet test band covers the target speed.
Ports & Layout

Single, dual, or stacked multi-port, with crosstalk and consistency requirements. RJ45 and transformer port counts must match.
PoE Role & Power

PSE / PD and af / at / bt power class, which set the center tap current rating and the RJ45 current rating.
Electrical Match

Turns ratio, OCL, insertion loss, return loss, CMRR, and isolation voltage against the PHY datasheet recommendations.
Temperature & Environment

Industrial or commercial temperature range, protection rating, salt spray or vibration requirements.
Package & Mounting

Height, footprint, SMT or through-hole, shielding or LEDs, and PCB layout and land pattern constraints.

FROM OUR REFERENCE DESIGNS

PHY, LAN Transformer and RJ45 Combinations in VOOHU Reference Designs

Each row lists the PHY or switch IC, LAN transformer and RJ45 jack placed together on one Ethernet port of a published VOOHU reference design. Open the reference design to see the full signal chain.

These combinations are taken from VOOHU reference designs and have not yet been individually confirmed by our FAE team, so please verify them with samples in your design and contact our FAE team if you need a combination confirmed. Contact our FAE team →

PHY / switch IC	Speed	VOOHU LAN transformer	VOOHU RJ45 jack / MagJack	Reference design
JL1101BR-NI JL1111B-NE PHY	10/100BASE-TX	WHSH16037D0 WHSH16F01D4	WH56A31882021103 WH56I3288RGGG0121101	AC EV Charger Battery Swap Cabinet / Station Data Logger / Comm Stick ESS Transformer / Grid-Tie Cabinet Smart Meter / Grid-Tie CT String Inverter
JL1101BR-NI PHY	10/100BASE-TX	WHS16037TG WHSH16F01D4	SYT561188AB1A1DB4 SYT561188DG1A3DY1027 SYT60A1188AB1A6DB3187	Distribution Feeder Protection & Control Unit Three-Phase 380V General-Purpose VFD
JL1101BR-NI PHY	10/100BASE-TX	WHS16002GA WHS16037TG WHSH16F01D4	SYT561188AB1A1DB4 SYT561188DG1A3DY1027 SYT60A1188AB1A6DB3187	7-inch Industrial HMI Mainboard
JL1101BR-NI JL1111BI-NI PHY	10/100BASE-TX	WHS16002GA WHS16037TG WHSH16F01D4	SYT561188AB1A1DB4 SYT561188DG1A3DY1027 SYT60A1188AB1A6DB3187	Compact Safety PLC
JL1101BR-NI JL1111B-NI PHY	10/100BASE-TX	Built into the MagJack	SYT111B127DB1A1DP SYT111B624JB2A1DDJP	PoE IP Camera
JL1111B-NE JL1111BI-NI PHY	10/100BASE-TX	WHS16002GA WHS16037TG	WH56I3288RGGG0121101	EtherCAT Remote I/O Module
JL1111BI-NI PHY	10/100BASE-TX	WHS16002GA WHS16037TG WHSH16F01D4	M12 D-coded socket on this design	Multi-turn Absolute Encoder
JL1111BI-NI PHY	10/100BASE-TX	Built into the MagJack	SYT212B579CD2A4D SYT312B002DB3A4DN	48V Low-Voltage Servo Drive EtherCAT Stepper Drive
JL5104C-NC JL5104C-NI Switch IC (integrated PHYs)	10/100BASE-TX	WHS16002-1PTG WHSH16012P4	WH56I3288RGGG0121101	PoE-Powered 10/100 IP Phone
JL5104C-NC JL5104C-NI Switch IC (integrated PHYs)	10/100BASE-TX	WHS16037TG	WH56I3288RGGG0121101	PoE-Powered 10/100 IP Phone
JL5104C-NI Switch IC (integrated PHYs)	10/100BASE-TX	WHSH16037D0 WHSH16F01D4	WH56A31880021101 WH56I3288RGGG0121101	Billing Control Unit (TCU) C&I ESS PCS
JL5104C-NI JL5106C-NI Switch IC (integrated PHYs)	10/100BASE-TX	WHS16002GA WHS16037TG WHSH16F01D4	SYT561288AB2A3DY1027 SYT561288DB1A3DY1027	Compact PLC CPU Module
JL2101C-NC JL2101C-NI PHY	10/100/1000BASE-T	WHLT-4532B-201MGF WHLT-4532B-351MGF WHLT-4532E-201MGN	SYT561288AB2A3DY1027 SYT561288AE6A3DY1027 SYT561288DB1A3DY1027	GPON ONU Home Gateway
JL2101C-NC JL2101C-NI PHY	10/100/1000BASE-T	Built into the MagJack	SYT211Q066CD2A4D SYT311Q010DB1A4DHDB	24-Port Gigabit L2 Managed Access Switch 5G Base Station BBU + AAU Aggregation Switch Firewall / Security Gateway OLT (Central Office) Spine Switch TOR / Leaf Switch
JL2101C-NC PHY	10/100/1000BASE-T	Built into the MagJack	SYT211Q066CD2A4D	Storage / GPU Server
JL2101C-NC JL2101C-NI PHY	10/100/1000BASE-T	Built into the MagJack	SYT211Q066CD2A4D	Server + NIC
JL2101C-NI PHY	10/100/1000BASE-T	WHSG24002TG WHSG24R03D0	SYT561188AB1A1DB4 SYT561188DG1A3DY1027	Engineering / Operator Workstation Mainboard
JL2101C-NI PHY	10/100/1000BASE-T	Built into the MagJack	SYT211Q066CD2A4D	Optical Cable / Fiber Infrastructure OTN / DWDM Optical Transport Transport / Metro Network
JL2308-PC JL2308-PI 8-port PHY	10/100/1000BASE-T	WHSG48001TG	SYT59212488DB1A1DY1B022	Enterprise Router / Egress Gateway
JL2388-PC JL2388-PI 8-port PHY	10/100/1000BASE-T	WHSG48001TG	SYT59212488DB1A1DY1B022	Firewall / Security Gateway
JL2388-PC JL2388-PI 8-port PHY	10/100/1000BASE-T	Built into the MagJack	SYT26Q042DB2A4D068 WH59G81016623C WH59G82606623C12	24-Port Gigabit L2 Managed Access Switch
JL6107-PC JL6107-PI Switch IC (integrated PHYs)	10/100/1000BASE-T	WHSG48001TG	SYT561488AB1A3DY1027 SYT561488DB1A3DY1027	Industrial 5G Router (5G CPE)
JL6107-PI JL6107S-PI Switch IC (integrated PHYs)	10/100/1000BASE-T	WHSG24701D1 WHSG48001TG	SYT561488AB1A3DY1027 WH56I3288RGGG0121101	EMS Energy Management Controller
JL6107S-PC JL6107SC-PC Switch IC (integrated PHYs)	10/100/1000BASE-T	WHSG24002G WHSG24301G WHSG24701G	SYT561288AB1A3DY1027 SYT561288AB2A3DY1027 SYT561288DB1A3DY1027	Home Wi-Fi 6 Router
JL6107S-PC JL6107SC-PC Switch IC (integrated PHYs)	10/100/1000BASE-T	WHLT-4532B-201MGF WHLT-4532E-201MGN	SYT561288AB1A3DY1027 SYT561288AB2A3DY1027 SYT561288DB1A3DY1027	Home Wi-Fi 6 Router
JL6107S-PC JL6107SC-PC Switch IC (integrated PHYs)	10/100/1000BASE-T	Built into the MagJack	SYT112Q066DA1A1D SYT112Q066DA2A1D SYT112Q070AE4A1D3	Home Wi-Fi 6 Router
JL6107S-PI JL6110-PI Switch IC (integrated PHYs)	10/100/1000BASE-T	WHSG24301GM WHSG48001TG	SYT561488AB1A3DY1027 WH56I3288RGGG0121101	Industrial Switch / Industrial PSU
JL6110-PC JL6110-PI Switch IC (integrated PHYs)	10/100/1000BASE-T	WHSG48002PG WHSG48603PTG	SYT59212488DB1A1DY1B022 SYT59212488DB1A1DY1C022	8-Port Gigabit PoE+ Switch
JL4201-NC JL4201-NI PHY	2.5GBASE-T	WHSQ24002TG WHSQ24015T0	SYT561288AB2A3DY1027	Engineering / Operator Workstation Mainboard
JL4201-NC JL4201-NI PHY	2.5GBASE-T	Built into the MagJack	SYT411F570DF5A2DP359	Wireless AP
JL1101 / JL1111 series PHY	10/100BASE-TX	10/100BASE-TX LAN transformers	RJ45 jacks without magnetics	Category level: LAN transformer product pages
JL2101 series PHY	10/100/1000BASE-T	Gigabit LAN transformers	RJ45 jacks without magnetics	Category level: LAN transformer product pages

A MagJack is an RJ45 jack with integrated magnetics, so no separate LAN transformer is needed.
VOOHU is an authorized distributor for JLSemi Ethernet PHY and switch ICs; the LAN transformers and RJ45 jacks are VOOHU parts.
The last two rows are category-level pairings from the Works with section of our LAN transformer product pages; they do not name a specific part.

Before You Select

Matching Product Lines

These are related categories. Confirmed parts for your PHY come with the reply, including document versions and operating conditions.

Downloads

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Published Reference Designs

Reference designs apply to specific PHYs and test conditions and may not apply to your application.

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PHY Selected. Which Transformer and RJ45 Fit?

Situations You May Be Facing

PHY or Switch Chip Already Selected

Multi-Port or High-Speed Design

PoE Is Involved

Space or Mounting Constraints

Get a Matched Combination in Three Steps

Share PHY and Application

Engineer Matching

Get Combinations and Documents

How We Match

Speed & Interface

Ports & Layout

PoE Role & Power

Electrical Match

Temperature & Environment

Package & Mounting