Providing solutions for the Si3406x and Si3404 high-efficiency multi-function PD families

Silicon Labs announced the introduction of two new Power over Ethernet (PoE) Powered Device (PD) families that deliver best-in-class integration and efficiency for Internet of Things (IoT) applications.

Silicon Labs' Si3406x and Si3404 product families integrate the necessary high-voltage discrete components into a single PD chip. These PD ICs support IEEE 802.3at standard PoE+ power performance, flexible power conversion options with over 90% efficiency, sleep/wake/LED support modes, and superior EMI immunity. These features enable developers to reduce system development costs and time to market for high-power, high-efficiency PoE PD applications.

The rapid expansion of the Internet of Things (IoT) is driving demand for PoE+ connectivity in IP cameras, smart lighting fixtures, multi-function video IP phones, advanced 802.11 wireless access points, and smart home appliances. These applications are driving demand for PoE+-compliant PD devices, which typically require high power. The latest motorized IP cameras with pan/tilt/zoom capabilities and heater elements place significant demands on power supplies. PoE+ technology provides 30W of power for these applications. Silicon Labs' Si3406x family of products is a PD interface solution suitable for a new class of IoT products supporting PoE+ in residential, commercial and industrial environments.



“Silicon Labs’ PoE solutions provide a wide range of power levels up to 30 W to meet our customers’ demanding powering needs,” said Ross Savolcic, vice president and general manager of power products at Silicon Labs. “Our PD family of products offers industry-leading integration and advanced features to help developers simplify their designs and meet their power and cost budgets. For both ends of the Ethernet cable, Silicon Labs’ one-stop-shop PoE portfolio includes the new PD devices as well as Power Sourcing Equipment (PSE) controllers and PSE power management ICs.”

Silicon Labs' Si3406x ICs integrate all the power management and control functions required for PoE+ PD applications, converting the high voltage supplied over 10/100/1000BASE-T Ethernet cables into an appropriately low-voltage output. This optimized architecture maintains high performance while using economical external components, minimizing PCB footprint and external bill of materials (BOM) costs.

Complementing the Si3406x family, the Si3404 IC provides cost-effective 802.3 Type 1 compatibility for low-power 15W PoE PD applications. The Si3404 integrates all the interfaces and control functions required for low-power PD applications into a small footprint.

The Si3406x ICs integrate a diode bridge and a transient surge suppressor, allowing direct connection to an Ethernet RJ-45 connector. The regulator's switching frequency can be easily adjusted using external resistors to avoid unwanted harmonics. An integrated synchronous driver controls the secondary field effect transistor (FET) to improve power conversion efficiency. The connection to the PSE switch during sleep mode is maintained by an automatic maintain-power-signature (MPS) function.

The Si3406x family of current-mode switching regulators supports a variety of isolated and non-isolated power supply topologies. These regulators are complemented by integrated power switching FETs. This flexibility, combined with Silicon Labs' comprehensive PoE PD reference designs, allows developers to easily design core power supply subsystems.