The LTC4267-3 combines an IEEE 802.3af compliant Powered Device (PD) interface with a 300kHz current mode switching regulator, providing a complete power solution for PD applications. The LTC4267-3 integrates the 25k signature resistor, classification current source, thermal overload protection, signature disable and power good signal along with an undervoltage lockout optimized for use with the IEEE-required diode bridge. The LTC4267-3 provides an increased operational current limit, maximizing power available for class 3 applications.The 300kHz current mode switching regulator provides higher output power or smaller external size compared to its lower frequency counterparts. The LTC4267-3 is designed for driving a 6V rated N-channel MOSFET and features programmable slope compensation, soft-start, and constant-frequency operation, minimizing noise even with light loads. The LTC4267-3 includes an onboard error amplifier and voltage reference allowing use in both isolated and nonisolated configurations.The LTC4267-3 is available in a space saving, low profile 16-pin SSOP or DFN packages.ApplicationsIP Phone Power ManagementWireless Access PointsSecurity CamerasPower over Ethernet