defining a degree of excellence

Corporate Office

Bel Fuse Inc.

198 Van Vorst Street, Jersey City, NJ 07302-4496

Tel: 201-432-0463

Fax: 201-432-9542

E-Mail: BelFuse@belfuse.com

Internet: http://www.belfuse.com

Far East Office

Bel Fuse Ltd.

8F/8 Luk Hop Street

San Po Kong

Kowloon, Hong Kong

Tel: 852-2328-5515

Fax: 852-2352-3706

European Office

Bel Fuse Europe Ltd.

Preston Technology Management Centre

Marsh Lane, Preston PR1 8UD

Lancashire, U.K.

Tel: 44-1772-556601

Fax: 44-1772-888366

APPLICATION NOTES

• Bel has developed these part types for use with AMD's product line of quad, 4-port PHY devices that incorporate

digital filtering techniques within the silicon itself. Bel's "filterless magnetics" are optimized for this specific application

and create a very cost efficient design solution. Each Bel part type contains 4 channels of transmit and receive

transformers to provide for wave shaping, high voltage isolation and EMI noise suppression. In certain applications,

additional differential filtering may be required to comply with IEEE 802.3 standards.

• Bel has designed these parts as a family of parts with common footprint and pinouts to enable the designer to

customize the use of common mode choke for optimum system performance.

• In multi-port system applications, good PCB layout and proper grounding techniques are very critical to achieve FCC

class A and B equipment approvals. Bel recommendations are available and can be provided by contacting our

engineering department or your local sales representative.

• Bel's low profile, surface mount packaging is ideal for high speed pick and place machinery. Parts can be shipped on

tape and reel for high speed placement. Construction processes have been implemented for thermal compatibility

with high temperature IR reflow assembly processing. Post dipping of leads assist with PC board solderability. Each

part is optically inspected to meet rigid coplanarity requirements.

• The specific configuration of these Bel parts (Rx-Tx-Tx-Rx-Rx-Tx-Tx-Rx) is optimal for use with stacked or "double

decker" RJ-45 connectors. This configuration should provide short and straight traces to the output connectors.

960049A

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