LTC4258 is a quad –48V Hot Swap TM controller de- signed for use in IEEE 802.3af compliant Power Sourcing Equipment (PSE). It consists of four independent ports, each with output current limit, short-circuit protec- tion, complete Powered Device (PD) detection and classi- fication capability, and programmable PD disconnect using DC sensing.
The LTC4258 provides four independent –48 V powered Ethernet ports, each with IEEE 802.3af compliant PD detection, classification, current limiting, short‑circuit protection and power‑good indication. It can operate autonomously or be controlled via an I²C interface, allowing up to 64 ports to be managed with only two digital lines.
The device is supplied in a 36‑lead SSOP package and includes detailed pin functions, absolute maximum ratings, electrical characteristics, timing diagrams and typical application schematics for both isolated and non‑isolated Power over Ethernet designs.
| Vpp Supply Voltage | 3.3 V (typ) |
|---|---|
| Supply Current (Vop) | 5 mA (typ) |
| Operating Temperature Range | 0 °C to 70 °C |
The Vpp pin can be powered from –0.3 V to 5 V.
It controls four independent –48 V powered Ethernet ports.
The device is programmed via an I²C serial interface.
It is available in a 36‑lead plastic SSOP (wide) package.