Comparison of Lan Transformer With Chip Lan

Comparison of  LAN Transformer With Chip Lan

In recent years, LAN ports have come standard not only for IT equipment such as computers, but also for everything from digital TVS

On AV devices. LAN transformer is the key component of LAN port. It's the key to transmitting pulse signals at high speeds


The new split transformer (CHIP LAN) is a solution for typical Ethernet applications. The innovative design uses equivalence

The circuit replaces the traditional LAN transformer. All components in the circuit can be manufactured automatically, and are SMD type, reducing the product

The model also eliminates the complicated process of the traditional network transformer.

Zhuhai Eastever Electronic Co., Ltd. applies and develops the technology accumulated in wound common mode inductor products, which is newly developed using all self

The dynamic winding process of the new separation transformer (CHIP LAN), to provide customers with more LAN port device supporting options.



Functional characteristics Chip LAN

Chip LAN

Traditional LAN Notes
Signal transmission Capacitor dc isolation Electro magnetic coupling Electromagnetic coupling

Chip Lan (capacitive type) : Signal propagation is carried out by means of capacitive isolation of DC signal and pulse signal principle

Traditional LAN transformer &Chip LAN (inductive type) : Signal transmission is carried away by the electromagnetic coupling of the main transformer

High voltage isolation /



Chip Lan (capacitive) : This function cannot be satisfied

The traditional LAN transformer is met by insulated wire and insulating glue in the main transformer winding

Chip LAN (inductive type) : meets through insulated wires in the main transformer windings

Impedance matching Equivalent circuit of capacitor/common-mode inductor/self-coupling transformer Transformer coil ratio Transformer coil ratio

Chip Lan (capacitive) : CAP+CMC+AUTO C"FMR combined equivalent circuit

Traditional LAN transformer &Chip LAN (inductive type) : primary and secondary winding turns ratio of the main transformer

Noise suppression Common-mode inductor/self-coupling transformer Center tap/ common mode inductor Center tap/ common mode inductor/self - coupling transformer The Chip Lan(capacitive)/ Traditonal LAN transformer /Chip Lan(inductive) is the same
POE Support N/A







The traditional LAN transformer /Chip Lan (inductive type) is the same
Surger Protect Self-coupled transformer Transformer
Bob Smith Circuit
Bob Smith Circuil

Chip Lan(capacitive) uses a self-coupled transformer to provide a low impedance conduction to a Surge common-mode pulse

The traditional LAN transformer / Chip Lan (inductive type) uses the transformer for isolation, 2Kv capacitor protection

TVS should be added to clamp if necessary.


    Automatic winding & spot welding              Automatic dispensing & Assembly & baking                         Automatic test package



一、Test scheme

1. Traditional 10/100Base-Tx transformer: ES16503G

2. Inductive LAN transformer: CMF-4532B-201MGN+LC-2012A-801T0

3.Capacitive LAN transformer:CMF-3216A-600M0+LC-2012A-801T0

Quantity: 10 groups of data each.

二、Test method

1. Traditional transformer: direct single unit test.

2. Inductive LAN transformer & Capacitive LAN transformer: inductive network becomes a 4532 and a 2012 combined to form a whole, capacitive network becomes a 3216 and a 2012 combined to form a whole, so it needs to be welded on the PCB board for testing as shown in the figure below:


           Traditional Transformer                                      Inductive LAN transformer                                             Capacitive LAN transformer

Test Item OCL/LX(uH) LK(uH)

Test Conditions

100KHZ,0.1V with 8mA DC Bias 100KHZ,0.1V

traditional type

(sensing value of main transformer)

621 535 592 581 531 0.15 0.18 0.14 0.13 0.16
559 592 521 540 569 0.17 0.13 0.15 0.14 0.17

Inductive type

(sensing value of main transformer)

288 284 301 260 287 0.30 0.22 0.28 0.26 0.25
298 317 278 293 280 0.24 0.24 0.23 0.22 0.25

Capacitive type

(sensing value of main transformer)

252 258 255 260 258 NA
260 251 253 254 254
Test Item DCR(Ω)
Test Conditions Because the inductance and capacitance products are welded to the PCB test board for testing, the measured resistance values include the parasitic parameters on the PCB board
Traditional type 0.55 0.55 0.55 0.55 0.53 0.55 0.53 0.54 0.53 0.54

Inductive type

2.39 2.39 2.51 2.42 2.69 2.42 2.38 2.53 2.47 2.40
Capacitive type 2.43 2.55 2.46 2.60 2.56 2.60 2.50 2.45 2.49 2.50

Notes:For low frequency parameters, the access inductance & resistance of the traditional LAN transformer is better than that of inductive and capacitive schemes.






Sum up:

According to the above data comparison of traditional Lan transformer, inductive Lan transformer and capacitive Lan transformer:

1. In terms of low-frequency parameters, the parameters of the traditional Lan transformer access system are better than those of capacitive and inductive Chip Lan schemes;

2. From the perspective of high-frequency data,

a. Consistency: inductive and capacitive data consistency is better than traditional Lan transformers;

b. Parameter performance: The performance of plug loss and return loss parameters capacitive and inductive Lan transformers is better than that of traditional Lan transformers, and the performance of CMRR parameters traditional Lan transformer is better than the other two.

3. POE performance

a. Chip Lan inductance scheme has the same performance as conventional transformers, up to 90W depending on selection.

b. The Chip Lan capacitor scheme is not usually used in POE circuits.

4. Surge Protect

A. Chip Lan(capacitive) uses a self-coupled transformer to provide low-impedance ground conduction for Surge common-mode pulses, with the lowest cost protection solution and up to 6Kv support.

b. The traditional network transformer /Chip Lan(inductive type) uses the transformer for isolation, and TVS should be increased when necessary for 2Kv capacitor protection

Row clamp, relatively high cost.






James  Wang

Tel:+86-756-8898808-615    Mobile: +86-15916247698
QQ: 878671401         Skype:zhyuefa

Helen   Xie

Tel:+86-756-8898808-603    Mobile: +86-13825697115

QQ: 2026402119        Skype:2026402119


Karmen  Wu

Tel:+86-756-8898808-602    Mobile: +86-13760523235

QQ: 3172926050        Skype:13760523235



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