New Industry Products

TI Introduces PoE Manager for Power Source Equipment that Delivers 25 Watts

December 18, 2006 by Jeff Shepard

Texas Instruments Inc. (TI) introduced its TPS23841, which the company claims is the industry's first fully integrated power-over-Ethernet (PoE) management device for power source equipment (PSE) that allows multiport enterprise systems to deliver up to 25W of power over a standard Ethernet cable, nearly twice the capability of previous generation systems.

Working from a 21.5 to 57V input to accommodate a wide range of medical and industrial applications, the quad-port IC provides power management control and protection, while safely delivering up to 665mA per port. Simplifying PoE design, the chip integrates four 15-bit analog-to-digital (A/D) converters, plus sense resistors and power switches, to allow the device to accurately measure signature resistance, voltage, current and die temperature. The device also can be designed in with the company's TPS2384 power source equipment manager to enable high power and standard PoE operation in a system running on the same comprehensive software.

The TPS23841 also provides three different options – automatic mode, semi-auto mode, or manual operation – that give designers added flexibility to meet specific PoE system requirements. While in manual mode, the TPS23841 can work with a microcontroller, such as the company's MSP430 ultralow-power microcontroller, to detect legacy capacitance loads.

The TPS23841 meets all power requirements of the company's 8-pin, TPS2376-H powered device (PD) controller for Ethernet-powered devices. The TPS2376-H contains all of the safety features needed to develop a powered device with programmable, 600mA current limit and thermal shutdown, auto-retry, and fault protection.

The TPS2376-H also allows designers to implement non-standard PDs that draw up to 26W from source equipment (minimum 52-volt input) over 100 meters of CAT-5 Ethernet cable. The PD controller and the TPS23841 manager are both compatible with the most recent decisions of the IEEE 802.3at committee, which has responsibility for the emerging PoE+ standard.

The TPS23841, in a 64-pin HTQFP package and rated for operation over -40 to +125°C, has a suggested resale price of $7.50 each in quantities of 1,000 units.