[原创] Linear LT4276IEEE 802．3af／at和LTPoE++受电设备解决方案

Linear公司的LT4276是LTPoE++/PoE+/PoE PD正激式/反激式控制器,支持LTPoE++ 38.7W,52.7W,70W和90W标准以及EEE 802.3at (25.5W) 规范,IEEE 802.3af (高达 13W) 规范,具有出众的浪涌保护能力,主要用在大功率无线数据系统,户外监视照相机设备,商用和公共信息显示器以及高温应用.本文介绍了LT4276主要特性,框图,多种应用电路以及演示板2046A-A特性,电路图和材料清单.

The LTR4276 is a pin-for-pin compatible family of IEEE802.3 and LTPoE++ Powered Device (PD) controllers. Itincludes an isolated switching regulator controller capableof synchronous operation in both forward and flybacktopologies with auxiliary power support.

The LT4276A employs the LTPoE++ classification scheme,receiving 38.7W, 52.7W, 70W or 90W of power at the PDRJ45 connector, and is backwards compatible with IEEE802.3. The LT4276B is a fully 802.3at compliant, 25.5WType 2 (PoE+) PD. The LT4276C is a fully 802.3af compliant,13W Type 1 (PoE) PD.

The LT4276 supports both forward and flyback powersupply topologies, configurable for a wide range of PoEapplications. The flyback topology supports No-Optofeedback. Auxiliary input voltage can be accurately sensedwith just a resistor divider connected to the AUX pin.
..

查看全文