Date: 17/10/2012

Integrated, green-mode controllers from TI for PoE powered applications

Texas Instruments Incorporated (TI) has announced two power management ICs that combine a Power over Ethernet powered device (PD) manager with a DC/DC controller. The TPS23751 and TPS23752 controllers achieve high conversion efficiency over a wide load range and light load efficiency. These integrated chips are designed for use in IEEE 802.3at type 2 (high-power) compliant PoE designs, used in IP phones, surveillance cameras, wireless access points, as well as various industrial applications.

The new PoE solutions join TI's family of PD controllers, including the TPS2378 and TPS2379. The TPS2378 features IEEE 802.3 type 2 compliance and is interoperable with the UPOE Ethernet implementation, which delivers 25.5 W to 51 W over Ethernet CAT-5 cables using the four-pair technique. The TPS2379 delivers higher output power capability with the addition of an external FET to control loads from 50 W to 100 W.

Features of TPS23751 and TPS23752:
1. IEEE 802.3at type 2 compliant: Both devices generate up to 25.5-W to the PoE loads.
2. Efficient Green-mode operation: During light load conditions, both devices switch off the synchronous rectifier and go into variable frequency operation. This feature allows efficiencies greater than 80 percent at 20 percent load operation and maintains high efficiency from very light to full load.
3. Integrated single-chip package: The circuits include an integrated DC/DC controller to convert input voltage to 3.3-V, 5-V or 12-V.
4. Deep sleep capability saves energy (TPS23572): The sleep-mode feature continues generating the maintain power signature after disabling the converter to reduce power consumption.

The company also provides evaluation modules (EVMs) as well as an application note, "Implementing a 60-W, End-to-End PoE System" for quick evaluation and design with these devices.

The devices are available to sample and purchase today. Packaging and suggested retail pricing in 1,000-unit quantities are as follows:
1. TPS23751, 16-pin TSSOP: US$1.50
2. TPS23752. 20-pin TSSOP: US$1.50
3. TPS2378, 8-pin SOPowerPAD: US$1.00
4. TPS2379, 8-pin SOPowerPAD: US$1.00

For more information: visit: www.ti.com/poe-pr

Source: Texas Instruments