Feature-rich Si3406x and Si3404 powered device families target IoT

Silicon Labs has released two Power over Ethernet (PoE) Powered Device (PD) families suitable for a wide range of Internet of Things (IoT) applications.

The Si3406x and Si3404 families include all necessary high-voltage discrete components on a single PD chip. The PD ICs support IEEE 802.3 at PoE+ power capabilities, flexible power conversion options exceeding 90 percent efficiency, robust sleep/wake/LED support modes and enhancedEMI immunity.

These capabilities will help developers reduce system cost and time to market for high-power, high-efficiency PoE PD applications.

The rapid expansion of the IoT is boosting demand for PoE+ connectivity in IP cameras, smart lighting luminaires, feature-rich video IP phones, advanced 802.11 wireless access points and smart home appliances all of which require higher wattage driving and increasing demand for PD devices that support the PoE+ standard. PoE+ technology brings 30 watts of power to new classes of PoE+-enabled IoT products in residential, commercial and industrial environments.

The Si3406x ICs integrate all power management and control functions required for a PoE+ PD application, converting the high voltage supplied over a 10/100/1000BASE-T Ethernet connection to a regulated, low-voltage output supply. The architecture minimiaes printed circuit board (PCB) footprint and external BOM cost by enabling the use of economical external components while maintaining high performance.

Complementing the Si3406x family, the Si3404 IC offers cost-effective, 802.3 Type 1 compliant support for lower power 15W PoE PD applications. The Si3404 includes all interface and control functions required for low-power PD applications in a very small footprint.

The Si3406x ICs integrate diode bridges and a transient surge suppressor, enabling direct connection to an Ethernet RJ-45 connector. The regulator’s switching frequency is tunable with a simple external resistor value to avoid unwanted harmonics. An integrated synchronous driver can control a secondary side field effect transistor (FET) to improve power conversion efficiency. Connection to a PSE switch is maintained during sleep mode by an automated maintain-power-signature (MPS) feature.

The Si3406x family’s current-mode-controlled switching regulator supports multiple isolated and non-isolated power supply topologies. The regulator is complemented by an integrated power switching FET. This flexibility, along with Silicon Labs’ comprehensive PoE PD reference designs, are intended to make it easier for developers to deploy critical power supply subsystems.

Neil Tyler