LT4295 - IEEE 802.3bt PD Interface with Forward/Flyback Controller
Datasheet Documentation
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Typical Application

LT4295 Typical Application


The LT4295 is an IEEE 802.3af/at/bt(Draft 2.0)-compliant powered device (PD) interface controller with a switching regulator controller. The T2P output indicates the number of classification events received during IEEE 802.3bt-compliant mutual identification and negotiation of available power.

The LT4295 supports both forward and flyback power supply topologies. The flyback topology supports No-Opto feedback. Auxiliary input voltages can be accurately sensed with just a resistor divider connected to the AUX pin.

The LT4295 utilizes an external, low R DS(on) N-channel hot swap MOSFET and supports the LT4320/LT4321 ideal diode bridges, to extend the end-to-end power delivery efficiency and eliminate costly heat sinks.

The LT4295 also includes an on-chip detection signature resistor, thermal protection, slope compensation, and many user configurable settings including classification signature, inrush current, switcher frequency, gate drive delay, soft-start, and load compensation.


4x5 QFN-28

LT4295 Package Drawing
Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price
LT4295IUFD#PBF QFN 28 I $3.93 $2.75
LT4295HUFD#PBF QFN 28 H $4.71 $3.30
LT4295HUFD#TRPBF QFN 28 H $4.77 $3.36
LT4295IUFD#TRPBF QFN 28 I $3.99 $2.81
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC2475A-A LT4295/LT4321 Demo Board | PoE++ (40W, 12V/3A) PD with Flyback DC/DC and Ideal Diode Bridge $95.00
DC2476A-A LT4295/LT4321 Demo Board | PoE++ (71W/24V/2.7A or 62W/24V/2.3A) PD with Flyback DC/DC and Ideal Diode Bridge $95.00
DC2539A-A LT4295/LT4321 Demo Board | PoE++ (51W, 12V/3.9A) PD with Flyback DC/DC and Ideal Diode Bridge $95.00
DC2584A-A LT4295/LT4321 Demo Board | PoE++ (71W/12V/5.5A) PD with Forward DC/DC and Ideal Diode Bridge $95.00