Datasheet Summary
IEEE 802.3af PD Power over Ethernet Interface Controller
Features
- plete Power Interface Port for IEEE 802.3af® Powered Devices (PDs)
- Onboard 100V, 400mA Power MOSFET
- Precision Input Current Limit
- Onboard 25k Signature Resistor
- Programmable Classification Current (Class 0-4)
- Undervoltage Lockout
- Smart Thermal Protection
- Power Good Signal
- Available in 8-Pin SO and Low Profile (3mm × 3mm)
DFN Packages
U APPLICATIO S
- IP Phone Power Management
- Wireless Access Points
- Tele Power Control
DESCRIPTIO
The LTC®4257 provides plete signature and power interface functions for a device operating in an IEEE 802.3af Power over Ethernet (PoE) system. The...