PoE Chip Provides Auxiliary Power Source

The LM5071 takes position as the industry’s first single chip solution designed for Power over Ethernet (PoE) devices that operate from alternative power sources or the PoE-enabled network. Essentially a powered-device (PD) interface and dc/dc converter, the chip simplifies the design of a variety of PoE applications that require an auxiliary power source, such as an ac adapter. The chip integrates a PD front end that accepts power from the PSE (Power Sourcing Equipment) or auxiliary power, using the integrated converter to step down the input voltage for powering various PD loads. Features include a maximum input voltage of 80V, user-programmable oscillator frequency up to 1 MHz, over-temperature protection, a voltage reference and high-performance error amplifier for non-isolated applications, support for auxiliary power sources from 12V to 48V, and UVLO threshold and hysteresis. In lead-free and standard TSSOP-16 packages, price is $1.45 each/1,000. NATIONAL SEMICONDUCTOR CORP., Santa Clara, CA. (800) 272-9959.