The Si3402 is the industry’s most highly-integrated, IEEE 802.3at Type 1-compliant, PoE PD interface and pulse-width-modulated (PWM) switching regulator. By setting a new bar for device integration, lowest overall BOM cost, efficiency and reliability, the Si3402 enables designers to easily add PoE functionality to their Ethernet products. When included in the design of a PoE-enabled system, such as a wireless access point or VoIP phone, the Si3402 converts the high voltage (typically ±48 V) supplied over Ethernet copper UTP cabling into a regulated, low-voltage dc supply. In addition, the Si3402 combines all the required IEEE 802.3at Type 1 detection, classification and hot swap interfaces with a complete, high efficiency, PWM switching regulator.
The Si3402-B is a pin-compatible replacement for the End-of-Life Si3402-A. Existing customer products which were based on Si3402-A EVB reference designs can be readily re-used with minimal change to a few on-board components.