In Power over Ethernet (PoE) systems, lan transformers play a critical role in ensuring reliable power delivery and signal integrity. When selecting transformers for PoE applications, several technical factors must be prioritized.
1. Isolation Voltage: PoE transformers must provide high isolation (typically 1500V AC or higher) to protect sensitive equipment from voltage surges and ground loops, complying with IEEE 802.3af/at/bt standards.
2. Power Handling Capacity: The transformer must support the required PoE power class (up to 90W for IEEE 802.3bt) while minimizing resistive losses. Low DC resistance (DCR) windings are essential to reduce heat generation and improve efficiency.
3. Signal Integrity: High common-mode rejection ratio (CMRR) and low insertion loss are critical to maintain data transmission quality, especially in high-speed applications (1G/2.5G/10GBASE-T). Wide bandwidth (up to 100MHz) ensures compatibility with advanced Ethernet protocols.
4. Thermal Performance: Transformers must operate reliably under elevated temperatures caused by continuous power transfer. Materials with high thermal stability (e.g., high-grade ferrite cores) are recommended.
5. Size and Compliance: Compact designs are preferred for space-constrained applications, but without compromising regulatory certifications (UL, CE).
By balancing these factors, engineers can optimize PoE system performance, ensuring robust power delivery and uninterrupted data communication.
