SPoE Surface Mount Transformers Signal Transformer / Bel SPoE (Simplified Power Over Ethernet) Surface Mount Transformers offer a 3W to 27W power range, 9V to 57V input voltage, and 250KHz operating switching frequency. These transformers are optimized for high density boards and are used for isolation and splitting two power/digital signals. SPoE transformers rely on Ethernet cables to receive power and digital data signals for operating and processing and are designed to connect to an Ethernet network. Signal Transformer / Bel SPoE Surface Mount Transformers are ideal for VoIP phones, IP cameras, IPTV decoders, and network routers.