Linear LTCR4270 12端口90W PSE控制方案
Linear公司的LTCR4270/LTC4271芯片组是12端口PSE控制器,专为IEEE 802.3at Type 1 and Type 2大功率兼容的PoE系统而设计,采用变压器隔离通信协议来替代昂贵的光耦合器,可提供PD的最大功率为90W,支持两对和4对输出功率,1MHz I2C兼容的串行控制接口,主要用在PoE PSE交换/路由器和PoE PSE中跨.本文介绍了LTCR4270/LTC4271主要特性,典型应用电路和PoE系统框图.
The LTCR4270/LTC4271 chipset is a 12-Port Power Sourcing Equipment (PSE) controller designed for use in IEEE 802.3at Type 1 and Type 2 (high power) compliant Power over Ethernet (PoE) systems. Transformer-isolated communication protocol replaces expensive opto-couplers and complex isolated 3.3V supply resulting in significant BOM cost savings. The LTC4270/LTC4271 chipset delivers lowest-in-industry heat dissipation by utilizing low-RDS(ON) external MOSFETs and 0.25Ω sense resistors.
Advanced power management features include per-port 12- bit current monitoring ADCs, DAC-programmable current limit, and versatile fast shut-down of preselected ports.
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