ST
now offers 2 choices for Power-over-Ethernet (PoE) interface controllers
for powered device (PD) applications: the STHS2375x and the STHS4257x.
The primary difference between the two parts is that the STHS4257x
has an integrated signature resistor and the STHS2375x requires
an external signature resistor. These controllers provide power
to applications over your existing Ethernet cable. Both devices
are IEEE802.3af compliant. Typical applications are: VoIP phones,
web and security cameras, WLAN access points, POS terminals, internet
appliances, and RFID readers.