Silicon Labs SI3400-D-GM

Description
The Si3400 and Si3401 are fully integrated Power-over-Ethernet (PoE) powered device (PD) interfaces and switching regulators. They convert high voltage supplied over Ethernet connections into regulated, low-voltage output supplies. The optimized architectures minimize solution footprint, reduce external BOM cost, and enable the use of low-cost external components while maintaining high performance.
The Si3400 and Si3401 integrate required diode bridges and transient surge suppressors, enabling direct connection of ICs to the Ethernet RJ-45 connector. The switching power FET and all associated functions are also integrated. The integrated switching regulator supports isolated (flyback) and non-isolated (buck) converter topologies.
The Si3400 and Si3401 support IEEE STDTM 802.3-2005 (future instances are referred to as 802.3) compliant solutions as well as pre-standard products, all in a single IC. Standard external resistors connected to the Si3400 and Si3401 provide the proper 802.3 signatures for the detection function and programming of the classification mode. Startup circuits ensure well-controlled initial operation of both the hotswap switch and the voltage regulator.

Features
IEEE 802.3 standard-compliant solution, including pre-standard (legacy) PoE support
Highly-integrated IC enables compact solution footprints
Minimal external components
Integrated diode bridges and transient surge suppressor
Integrated switching regulator controller with on-chip power FET
Integrated dual current-limited hotswap switch
Support non-isolated and isolated switching topologies
Comprehensive protection circuitry
Transient overvoltage protection
Undervoltage lockout
Early power-loss indicator
Thermal shutdown protection
Foldback current limiting
Programmable classification circuit
Low-profile 5 x 5 mm 20-pin QFNPb-Free and RoHS-compliant

Applications
Wireless access points
Security cameras
Voice over IP telephones and adapters
Point-of-sale terminals
Internet appliances
Network devices
High power applications (Si3401)