LT4295IUFD#PBF - IEEE 802.3bt PoE PD Controller | Analog Devices
N.º da peça: LT4295IUFDPBF ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $4.09 | $4,09 |
| 10 | $3.8 | $38,00 |
| 100 | $3.51 | $351,00 |
| 500 | $3.36 | $1.680,00 |
| 1.000 | $3.27 | $3.270,00 |
LT4295IUFDPBF Visão geral
A PoE powered-device controller is the interface circuit that performs detection, classification, and inrush-current limiting on the power delivered over the Ethernet cable, then manages the downstream isolated (or non-isolated) DC-DC conversion. In the power-management hierarchy it sits between the Ethernet magnetics/diode bridge and the point-of-load converters, combining PD interface and PWM control in a single power management IC.
Key features include IEEE 802.3bt mutual identification with a T2P output that indicates the number of classification events received, single-signature PD topology support that eliminates the need for a second PD controller, and an integrated switching regulator controller supporting both forward and flyback topologies for high efficiency power conversion.
Technically, the LT4295 integrates a precision detection/classification engine with a current-mode PWM controller, allowing the entire powered-device front end and primary-side conversion control to be handled by one IC. The 60V rating and rugged hot-swap style inrush control protect the PD interface from cable surge events, while programmable oscillator frequency and soft-start allow optimization of transformer size and EMI signature.
Typical applications include IEEE 802.3bt Type 3/4 powered devices such as security cameras, wireless access points, IP phones, LED luminaires, and industrial network nodes. Demonstration Circuit 2476A pairs the LT4295 with the LT4321 ideal diode bridge controller as a reference design.
Design consideration: pair the LT4295 with the LT4321 PoE ideal diode bridge controller to minimize bridge diode losses and improve overall PD efficiency, especially at 802.3bt power levels.
This page synthesizes distributor pricing, verified drop-in alternatives, practical design notes, and application guidance not found together in the manufacturer datasheet.
Alternativas drop-in para LT4295IUFDPBF — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
LT4295HUF#PBF
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
LT4295IUFDPBF Classificações máximas e características elétricas
| Função | PoE PD Interface with Forward/Flyback Controller |
| PoE Standards Supported | IEEE 802.3af, 802.3at, 802.3bt |
| Number of Channels | 1 |
| Input Voltage Rating | 60 V |
| Maximum Power Capability | 71.3 W |
| Topology Support | Forward / Flyback |
| T2P Output | Indicates number of 802.3bt classification events |
| PD Signature | Single-signature (dual-signature possible, contact ADI) |
| Encapsulamento | 28-QFN (4x5 mm) with exposed pad |
| Package Code | UFD |
| Tipo de montagem | Surface Mount |
| Operating Temperature Grade | I grade (-40C to +125C) |
| Status RoHS | Compliant (#PBF suffix) |
| Reel Packaging Option | 500-unit reels via #TRMPBF suffix |
| 1ku List Price | 3.27 USD (per Analog Devices product page) |
| Evaluation Hardware | DC2476A (with LT4321 ideal diode bridge) |
| Status do ciclo de vida | Recommended for New Designs |
Guia de Configuração de Pinos do LT4295IUFDPBF ufd
Configuração de pinos para LT4295IUFDPBF (pacote ufd). Este dispositivo de potência possui terminais de gate, drain e source. Para pacotes não polarizados, consulte o datasheet do fabricante para a orientação exata do pino 1 e detalhes do footprint. Aplicações comuns incluem projeto de fontes de alimentação, acionamento de motores e comutação de cargas.
Nenhum dado detalhado de pinagem disponível para LT4295IUFDPBF.
Consulte a ficha técnica para a configuração completa dos pinos.
Aplicações típicas
LT4295IUFDPBF é adequado para 6 aplicaçãos: IP Security Cameras, Wireless Access Points, PoE LED Lighting and Luminaires, IP Telephony and Video Conferencing Endpoints, Industrial Network Nodes and IoT Gateways, 5G Small Cells and Network Infrastructure.
IP Security Cameras
The LT4295 fits PTZ and high-definition IP cameras because 802.3bt Type 3/4 delivers up to 71.3W, enough for motorized pan/tilt mechanisms, IR illuminators, and heaters that exceed the 25.5W ceiling of 802.3at designs. The integrated forward/flyback controller converts the 48V PoE rail to camera rails (12V motor, 3.3V/1.8V logic) from one IC, and the T2P output lets the SoC report negotiated power class for dynamic load management. Deployed between the Ethernet magnetics and downstream POL converters, it adds no switching noise to the video signal path while the 60V rating and inrush limiting protect against cable surge events typical of long outdoor runs.
Recomendado
Wireless Access Points
802.11ax/802.11be enterprise access points with multi-radio MIMO front ends routinely draw 30-70W, making them ideal 802.3bt Type 3/4 loads. The LT4295 performs detection, classification, and mutual identification on the PSE side of the cable, then drives a forward or flyback converter to generate the RF power amplifier and digital rails. Its single-signature PD architecture eliminates a second PD controller, reducing BOM in space-constrained ceiling-mounted enclosures. The switching regulator controller supports programmable frequency, letting designers push the conversion stage above the audible band and shrink transformer size - important for slim AP housings - while the I-grade -40C to +125C range covers both indoor and harsh outdoor installations.
Recomendado
PoE LED Lighting and Luminaires
PoE lighting systems distribute 802.3bt power over structured cabling to LED luminaires, smart drivers, and sensors. The LT4295's 71.3W capability covers high-output downlights and tunable-white fixtures, and its integrated flyback controller steps the 48V input down efficiently to LED string voltages without a separate PWM IC. The T2P classification output allows the luminaire controller to verify available power before ramping LED current, preventing brownouts on shared class budgets. Because lighting fixtures are sealed and passively cooled, the exposed-pad 28-QFN package's thermal performance and the I-grade temperature rating support enclosed-ceiling environments where ambient temperatures can reach 85C near drivers.
Recomendado
IP Telephony and Video Conferencing Endpoints
Conference phones and video bar endpoints use PoE as their sole power source, and 802.3bt-rated units need more than the 12.95W that 802.3af provides once large touch displays and multi-element speaker arrays are added. The LT4295 handles detection and classification per 802.3af/at/bt automatically, so a single hardware platform can serve all three cable classes. Its forward/flyback controller generates isolated or non-isolated rails for audio amplifiers and the display, and the 60V tolerance withstands transient events on building cabling. The QFN footprint suits the thin PCBs used in wall-mount endpoints, and the PD front end conforms to IEEE 802.3 timing requirements for reliable handshakes with switches from any vendor.
Recomendado
Industrial Network Nodes and IoT Gateways
Factory-floor gateways, edge computers, and 5G small-cell nodes increasingly run on PoE to avoid dedicated power wiring in hazardous or retrofit locations. The LT4295's I-grade -40C to +125C operating range and 60V rating suit unconditioned industrial cabinets, while the integrated inrush control provides controlled hot-plug insertion onto live Ethernet runs. Its single-signature PD interface plus forward/flyback controller converts one IC's worth of board area into the entire PD power front end, freeing layout space for isolation and communication circuitry. Reference design DC2476A demonstrates a complete 802.3bt PD with the LT4321 ideal diode bridge, reducing design risk for industrial teams adopting PoE power for the first time.
Recomendado
5G Small Cells and Network Infrastructure
Outdoor 5G small cells and macro-assist nodes commonly draw 40-70W and are deployed where AC wiring is impractical, making 802.3bt Type 4 the preferred feed. The LT4295's 71.3W capability and 60V input rating directly match these budgets, and the flyback controller supports the isolated auxiliary rails small-cell radios require. The T2P output reports how many classification events occurred during 802.3bt mutual identification, letting the baseband processor adapt RF transmit power to the negotiated class. Surge robustness on the PD interface is essential on tower-mounted cable runs, and the LT4295's PoE front end, combined with the LT4321 ideal diode bridge in the ADI reference design, provides a field-proven power entry architecture.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para LT4295IUFDPBF — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | LT4295HUF#PBF |
|---|---|---|
| Package | 28-QFN (4x5 mm, UFD) | 28-QFN (4x5 mm, UFD) - same |
| Brand | Analog Devices | Analog Devices |
| PoE Standards | 802.3af / 802.3at / 802.3bt | 802.3af / 802.3at / 802.3bt |
| Max Power | 71.3 W | 71.3 W |
| Input Voltage Rating | 60 V | 60 V |
| Switching Topology | Forward / Flyback | Forward / Flyback |
| Operating Temperature | I grade (-40C to +125C) | H grade (wider range, per ADI family) |
| T2P Classification Output | Yes | Yes |
Principais diferenciais
- Full 802.3bt Type 3/4 support up to 71.3W in a single PD controller (vs LT4276)
- Integrated PD interface plus forward/flyback switcher controller (vs Discrete PD controller + separate PWM IC)
- T2P classification-event output for power budget management (vs LT4295HUF#PBF (equivalent) / older PD ICs without class reporting)
- Trade-off: proprietary footprint limits second sourcing (vs Generic PD interface ICs)
Notas de projeto
At 802.3bt Type 4 power levels approaching 71.3W, input bridge diode losses become the dominant efficiency penalty: four silicon diode drops at roughly 0.7V each across a 57V PSE rail can waste several watts. Use the LT4321 ideal diode bridge controller with low-Rds(on) MOSFETs, as implemented in ADI Demonstration Circuit 2476A, to cut bridge losses by an order of magnitude. Also size the input bulk capacitor to hold the VPORT rail through 802.3bt MPS (maintenance power signature) intervals without tripping PSE disconnect timers.
Estimated: the 28-QFN (UFD) exposed-pad package relies on the PCB for heat removal. At 71.3W output and, for example, 90% conversion efficiency, roughly 7.9W is dissipated across the PD front end, inrush MOSFET, and converter stage combined. Connect the exposed pad to a solid ground plane with an array of thermal vias to spread heat; inadequate copper pours will cause the junction to exceed the +125C I-grade limit in sealed enclosures. Verify junction temperature with a thermal model or IR measurement at maximum class load.
The LT4295 datasheet scopes its PD descriptions to single-signature topologies; dual-signature 802.3bt deployments (two powered pairs sets independently classified) require contacting Analog Devices applications engineering before committing to the design. Additionally, do not omit the classification event monitoring on T2P if the system firmware adapts its load budget to the negotiated class - skipping it risks overloading a Type 3 PSE. Confirm ordering suffix: standard #PBF tray vs 500-unit #TRMPBF reels through designated sales channels.
Keep the hot-swap and switcher power loops tight: the GATE drive, current-sense, and transformer primary connections should be short, wide traces with the loop area minimized to limit radiated EMI - important since the Ethernet cable is a known antenna path. Place the RT oscillator resistor away from switching nodes to avoid frequency jitter, and follow the DC2476A reference layout for transformer selection and snubber placement, which addresses both conducted and radiated emissions for 802.3bt compliance testing.
Informações de conformidade
RoHS compliance indicated by the #PBF (lead-free) suffix per Analog Devices naming convention. REACH, halogen-free, and conflict-minerals status not stated in the provided web data.
