LT4276BHUFD#PBF
数据手册.pdf以太网供电控制器, 60V/2 mA, 300HZ 开关/时钟, QFN-28
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 125°C
