Linear Technology has introduced the LTC4274, a single-channel power over ethernet controller for power sourcing equipment required to provide IEEE 802.3at (25.5 W) or proprietary higher power levels.
The device provides up to 100 W over four-pair ethernet cabling and is fully compliant with the IEEE 802.3at PoE+ standard and backward compatible with the earlier IEEE 802.3af PoE standard.
To help conserve power, the controller delivers low heat dissipation by using low RDS(ON) MOSFETs and 0.25 Ω sense resistors.
Advanced power management includes prioritised fast shutdown, 14.5-bit voltage and current readback, 8-bit programmable current limits and 7-bit programmable overload current limits. A 1 MHz I2C interface allows a host controller to digitally configure the IC or query port readings.
