LT4276BIUFD#PBF

LTPoE++/PoE+/PoE PD 正激式 / 反激式控制器

The is an LTPoE++/PoE+/PoE powered device PD forward/flyback controller in 28 pin QFN package. This device is a pin to pin compatible family of IEEE 802.3 and LTPoE++ powered device PD controllers. It includes an isolated switching regulator controller capable of synchronous operation in both forward and flyback topologies with auxiliary power support. The LT4276B is a fully 802.3at compliant 25.5W type 2 PoE+ PD and no opto isolator required for flyback operation. The device supports both forward and flyback power supply topologies and can be configurable for a wide range of PoE applications. Auxiliary input voltage can be accurately sensed with a resistor divider connected to AUX pin. The LT4276B utilizes an external, low RDS ON N channel MOSFET for hot swap function which maximizes power delivery, efficiency, reduces heat dissipation and eases thermal design.

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IEEE 802.3at/af compliant

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Superior surge protection 100V absolute maximum

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Auxiliary power support as low as 9V

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Maximum PD powered device power of 25.5W

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External hot swap N channel MOSFET for lowest power dissipation and highest system efficiency

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Greater than 94% end to end efficiency with LT4321 ideal bridge

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Vin operating voltage is 60V VPORT, HSSRC

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Switching frequency of 300KHz at ROSC = 45.3Kohm to GND

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Maximum PG duty cycle is 66%

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Operating junction temperature range from -40°C to 85°C