Linglierte has launched a new PD interface controller to meet the market demand for high-power applications

For today's new power-hungry applications such as microcellular, base stations, signage, and outdoor thermal cameras, PoE+'s limited PD power delivery of only 25.5W is not enough. Linear Technology Corporation has officially launched the LT4275, an LTPoE++++, PoE+, and PoE-compatible powered device (PD) interface controller for applications requiring up to 90W of transmission power.

 

The LTPoE++ standard extends this power budget to 4 different power levels (38.7W, 52.7W, 70W, and 90W), thus meeting the needs of this market and enabling a complete high-power LTPoE++ system. The LTPoE++ standard uses a classification scheme that simplifies LTPoE++ Power Supply Equipment (PSE) controllers and LTPoE++ PD controllers to reliably communicate with each other while maintaining interoperability with IEEE standard devices. LT4275A (LTPoE++), LT4275B (PoE++), and LT4275C (PoE) efficiently power PD loads with just a single IC.

Unlike traditional PD controllers that integrate power MOSFETs, the LT4275 controls an external MOSFET to dramatically reduce total PD heat and maximize power efficiency, which is especially important at higher power stages. This novel approach allows users to change the size of the MOSFET to meet the specific thermal and efficiency requirements of the application, and if necessary, allows for the use of low RDS(ON) 30mΩ MOSFETs. The LT4275 recognizes PSE as Type 1 hardware that meets IEEE 802.3af 13W power stages, Type 2 hardware that meets IEEE 802.3 at 25.5W power stages, or LTPoE++ hardware that meets 38.7W to 90W power levels and delivers the corresponding power. For efficient power distribution, PD users can configure a classification that represents PD power usage. The 100V absolute maximum input voltage rating means that the LT4275 makes it very easy to withstand and protect the PD from the most common Ethernet voltage surges. A programmable auxiliary power pin with feature damage information provides support down to 9V. The LT4275 also includes a power-good output, built-in feature resistors, undervoltage lockout, and full thermal protection.

 

The LT4275 is available in industrial and automotive versions and supports an operating temperature range of -40°C to 85°C and -40°C to 125°C, respectively, in a small RoHS-compliant 10-pin MSOP or 3mm x 3mm DFN package.

 

The LT4275 provides an upgrade to Linear Technology's existing PD products, including LTC4265 PoE++ PD controllers, and can be seamlessly connected to any of Linear Technology's latest PSE controllers, including single-port LTC4274, 4-port LTC4266, and 12-port LTC4270/LTC4271 chipsets.

 

LT4275 Performance Overview:

* IEEE 802.3af/at and LTPoE++ powered device (PD) controllers

* LTPoE++ supports power stages up to 90W

* LT4275A supports all of the following criteria:

* LTPoE++ 38.7W, 52.7W, 70W, and 90W

* Meets IEEE 802.3 at 25.5W requirements

* Meets IEEE 802.3af requirements up to 13W

* LT4275B is IEEE 802.3at/af compliant

* LT4275C is IEEE 802.3af compliant

* 100V absolute maximum input voltage

* Integrated feature resistors

* External Hot Swap (Hot Swap?) N-channel MOSFETs achieve lowest power consumption and highest system efficiency

* Programmable auxiliary power supplies support voltages as low as 9V

* Available in a 10-pin MSOP and 3mm x 3mm DFN package

 

LT4275 Application Market

* High power wireless data system

* Outdoor security camera equipment

* Commercial and public information displays

* High temperature industrial applications

 

LT4275 Price & Availability

The LT4275 is available in quantities at $1.45 per thousand pieces.