Product Overview

The HF-84023 is a quad-port, surface-mount magnetics module designed for 10/100 BASE-TX Ethernet applications. It integrates the required isolation, coupling, and filtering magnetics in a compact SMT package, tailored for space-efficient PCB design in Ethernet modules, switches, or network interface devices.
Typical target applications include LAN switching hubs, network interface cards (NICs), embedded Ethernet motherboards, and other 10/100 Mbps systems requiring multiple RJ-45 ports.

Key Features

• Supports 10/100 Mbps BASE-TX Ethernet standard.
• Quad-port configuration (4 independent magnetics ports) — helps reduce board space and simplify BOM for multi-port Ethernet devices.
• Surface-mount technology (SMT) footprint — designed for automated assembly and compact design.
• Integrated magnetics module: typically includes transformer windings, common-mode chokes, isolation, and termination components (as is common in 10/100 magnetics modules).
• Suitable for high-density multi-port Ethernet applications thanks to its compact packaging.
• Complies with typical Ethernet magnetics isolation and performance requirements

Typical Benefits for Designers

• Confirm network speed requirement: If your system requires Gigabit (1000 Base-T) or higher, select accordingly; LP1188NL is optimized for 10/100 Base-T.
• Ensure the PCB layout accommodates transformer placement near the PHY or RJ45 magnetics path for optimal signal integrity.
• Consider the isolation voltage rating relative to the system safety/regulatory environment.
• Verify the suitability of the reflow profile (SMT) and the maximum component height, considering enclosure constraints.
• If PoE (Power-over-Ethernet) capability is required, ensure magnetics and RJ45 interface are rated accordingly (LP1188NL is for NON-PoE).

Typical Design/Board Layout Considerations

1. Ensure correct footprint and pad layout per the module’s mechanical drawing (refer to datasheet for pin-out and solder-pad dimensions).
2. Maintain correct isolation clearance around the magnetics to meet Ethernet isolation standards (typically 1500 Vrms or higher between windings).
3. Route differential pairs (Tx/Rx) in close proximity, controlled impedance, and maintain return path integrity to maximize signal integrity at 100 Mbps.
4. Consider placement relative to the RJ-45 connector: the magnetics are often placed immediately adjacent to the RJ-45 to minimize stub length and EMI.
5. Follow manufacturer’s recommendation for grounding/shielding: typically, the magnetics module shielding or drain pin should connect to chassis ground or signal ground as specified.
6. EMI/EMC: Use of integrated magnetics helps meet emissions/privacy specifications; still, layout must follow good practices (e.g., keep noisy switching away, maintain common-mode choke effectiveness, use proper decoupling).
7. Thermal & reliability: Although magnetics modules generally carry low losses, verify that ambient temperature, board reflow profile, and any nearby heat sources are considered (especially in dense, multi-port designs).