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Analog Devices Inc. LTC4274AIUHF-3#PBF
- Part No.:
- LTC4274AIUHF-3#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Power Over Ethernet (PoE) Controllers
- Package:
- 38-WFQFN Exposed Pad
- Datasheet:
-
LTC4274AIUHF-3#PBF.pdf
- Description:
- IC POE CNTRL 1 CHANNEL 38QFN
- Quantity:
- Payment:
- Shipping:
Inventory:116
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Product details
Overview
LTC4274AIUHF-3#PBF from Analog Devices is a single-port LTPoE++ Power Sourcing Equipment (PSE) controller delivering up to 70W to compatible Powered Devices (PDs), featuring proprietary 4-point detection, 14-bit current monitoring ADC, DAC-programmable current limit, and I²C interface up to 1MHz. It supports IEEE 802.3at Type 1/2 and operates in endpoint or midspan configurations for high-reliability PoE infrastructure.
For engineers reviewing the LTC4274AIUHF-3#PBF datasheet, LTC4274AIUHF-3#PBF pinout, LTC4274AIUHF-3#PBF application, or LTC4274AIUHF-3#PBF equivalent, key selection criteria include LTPoE++ 70W power grade, –40°C to 85°C operating range, 38-lead 5mm × 7mm QFN package with exposed VEE pad, and compatibility with 0.25Ω sense resistors for low thermal dissipation.
Technical Context
The LTC4274AIUHF-3#PBF implements a dual-mode detection scheme-2-point forced voltage and 2-point forced current-with high-capacitance legacy device immunity. Its detection logic ensures mutual identification between LTPoE++ PSE and PD while maintaining full backward interoperability with IEEE 802.3af/at PDs.
It features an integrated 14-bit ADC for port current sensing (30.5 µV/LSB resolution) and port voltage sensing (5.835 mV/LSB), with 30 dB 50–60 Hz noise rejection. The GATE driver delivers 12 V (typ) above VEE and includes fast pull-down (30 mA) for rapid fault shutdown.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Max PD Power | 70W LTPoE++ compliant output; enables high-power IP cameras, PTZ systems, and thin clients without external boost stages. |
| Detection Method | Proprietary 4-point detection (2-force voltage + 2-force current); eliminates false PD detection in noisy or high-capacitance environments. |
| Current Sensing | 14-bit ADC with 30.5 µV/LSB resolution; supports accurate real-time current readback and precise overcurrent protection at LTPoE++ levels. |
| I²C Interface | Up to 1 MHz operation; allows high-speed configuration and status polling in multi-port PSE systems with minimal bus overhead. |
| Sense Resistor | Optimized for 0.25 Ω external resistor; minimizes power loss and heat generation at 70W delivery, critical for thermal management in dense switch designs. |
| Operating Temp | –40°C to +85°C; qualified for industrial Ethernet switches, outdoor midspans, and telecom equipment deployed in uncontrolled environments. |
| Package | 38-lead 5 mm × 7 mm QFN with exposed VEE pad; provides low thermal resistance (θJA = 34°C/W) and robust mechanical mounting for PoE port-level reliability. |
Pinout & Package
Package: 38-lead (5 mm × 7 mm) plastic QFN with exposed pad connected to VEE (Pin 39), requiring soldering to PCB for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VEE (Pins 19, 20, 21, 22, 23, 39) | Main PoE supply return | Negative high-voltage rail (–45V to –57V); all VEE pins must be tied together and connected to exposed pad for safe current return and thermal conduction. |
| GATE (Pin 24) | MOSFET gate drive output | Drives external N-channel MOSFET gate up to 12 V above VEE; includes fast 30 mA pull-down for sub-µs fault shutdown. |
| SENSE (Pin 25) | Current sense input | Monitors voltage across 0.25 Ω sense resistor between SENSE and VEE; enables precise current limiting and foldback control. |
| OUT (Pin 26) | Port voltage monitor | Connects directly to PoE output; internal 500 kΩ pull-up to AGND when idle; triggers power-good flag when VOUT–VEE < 2.4 V. |
| AUTO (Pin 12) | Autonomous mode enable | Configures default register state on reset; allows standalone operation without host I²C controller for basic plug-and-play deployment. |
| INT (Pin 11) | Open-drain interrupt output | Asserts low on fault events (overcurrent, disconnect, classification error); eliminates need for continuous register polling in host firmware. |
| SCL / SDAIN / SDAOUT (Pins 6–8) | I²C serial interface | Separate SDAIN/SDAOUT pins simplify opto-isolation; supports 1 MHz clock for fast status updates across multi-port systems. |
Key Features
| Feature | Design Value |
|---|---|
| Proprietary 4-point PD detection | Ensures >99.9% detection reliability in presence of EMI, cable capacitance, or legacy devices-no false starts or missed PDs. |
| DAC-programmable current limit | Enables dynamic adjustment of ILIM threshold via I²C register (e.g., 102 mV for 802.3af, 204 mV for LTPoE++ 70W), supporting adaptive power allocation per port. |
| Versatile quick port shutdown | SHDN and MSD pins provide hardware-initiated, glitch-filtered (<1 µs) port disable-critical for safety-critical or hot-swap applications. |
| Midspan backoff timer | 2.5 s (typ) delay after midspan detection prevents race conditions in cascaded PSE deployments, ensuring deterministic power-up sequencing. |
| 2-pair and 4-pair power support | Configurable via register settings to deliver 70W over two or four data pairs-enables flexible cabling strategies without redesign. |
Applications
| IP Surveillance Systems | Industrial Wireless Access Points |
|---|---|
Use Scenario: Outdoor PTZ security camera with heater, blower, and 4K imaging requiring stable 70W PoE power over 100m Cat6a cabling. IC Role / Device Role / Timing Role: Single-port LTPoE++ PSE controller managing detection, classification, current-limited power delivery, and DC disconnect supervision. Use Value: Eliminates need for local AC power or separate power injectors; leverages existing Ethernet infrastructure while guaranteeing full 70W delivery with thermal headroom. | Use Scenario: Factory-floor Wi-Fi 6E access point with beamforming antennas and real-time IoT gateway functions deployed in temperature-variable environments. IC Role / Device Role / Timing Role: Autonomous PSE port enabling plug-and-play power-up via AUTO pin mode, with I²C monitoring for remote diagnostics and fault logging. Use Value: Reduces firmware complexity and BOM count by removing external microcontroller dependency; maintains IEEE 802.3at compliance for mixed-device networks. |
| Medical Imaging Terminals | Smart Building Control Hubs |
Use Scenario: Wall-mounted diagnostic display terminal with touch interface, biometric sensor, and local storage drawing sustained 65W under clinical workload. IC Role / Device Role / Timing Role: High-accuracy current/voltage sensing PSE controller providing real-time telemetry (14-bit ADC) and MPS dropout detection per IEEE 802.3at. Use Value: Enables predictive maintenance via current signature analysis; meets medical EMC requirements through low-noise analog front-end design. | Use Scenario: Central HVAC and lighting controller aggregating BLE/Zigbee sensors and driving relay banks in commercial office buildings. IC Role / Device Role / Timing Role: Midspan-compatible PSE controller with MID pin configuration, supporting legacy non-PoE switches while adding 70W capability to retrofit infrastructure. Use Value: Extends lifecycle of existing network gear; avoids costly fiber or AC rewiring; supports Class 4 PD negotiation for future-proof scalability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PSE controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC4274AIUHF-4#PBF | Delivers up to 90W LTPoE++ vs. 70W; higher ILIM threshold (221 mV) and extended VEE range tolerance. | Required for next-gen PDs exceeding 70W (e.g., AI edge servers, high-lumen projectors); not drop-in due to tighter thermal constraints. | Select only if system requires >70W per port and thermal design accommodates higher dissipation. |
| MAX5984AEUI+T | IEEE 802.3bt-compliant 90W PSE; supports 4-pair power only; no LTPoE++ mutual identification or AUTO pin mode. | Targets standards-based 802.3bt ecosystems; lacks proprietary detection robustness in mixed-legacy environments. | Choose for strict IEEE compliance and interoperability with certified 802.3bt PDs; avoid where LTPoE++ handshake or autonomous startup is needed. |
Compared with LTC4274AIUHF-4#PBF and MAX5984AEUI+T, the LTC4274AIUHF-3#PBF uniquely balances 70W delivery, backward compatibility with 802.3af/at, and autonomous operation-making it optimal for cost-sensitive, thermally constrained midspan or endpoint designs needing field-proven reliability without overengineering.
Availability
LTC4274AIUHF-3#PBF is available at Aetrix Electronics and suitable for IP surveillance systems, industrial wireless access points, medical imaging terminals, and smart building control hubs requiring stable component supply, long-term lifecycle assurance, and guaranteed LTPoE++ 70W performance.
Supply support for LTC4274AIUHF-3#PBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.
The LTC4274A product line was designed specifically for high-reliability, high-power PoE infrastructure-enabling LTPoE++ 38.7W to 90W delivery with proprietary detection, thermal efficiency, and seamless IEEE 802.3at interoperability.
FAQ
What is the maximum PD power supported by the LTC4274AIUHF-3#PBF?
The LTC4274AIUHF-3#PBF supports up to 70W of LTPoE++ power delivery to compatible Powered Devices. This rating is confirmed in the Absolute Maximum Ratings table and Product Family section of the official datasheet, where "LTC4274AIUHF-3" is explicitly designated as the 70W variant. It operates within IEEE 802.3at Type 1/2 compliance while extending beyond with Linear's proprietary LTPoE++ protocol.
Does the LTC4274AIUHF-3#PBF require an external microcontroller to operate?
No-the LTC4274AIUHF-3#PBF supports autonomous operation via its AUTO pin. When configured (tied to VDD or DGND), it initializes internal registers to predefined states and performs full detection, classification, and power-up without host I²C intervention. This makes the LTC4274AIUHF-3#PBF ideal for simple midspan or endpoint designs where firmware overhead must be minimized.
What is the purpose of the separate SDAIN and SDAOUT pins on the LTC4274AIUHF-3#PBF?
The LTC4274AIUHF-3#PBF uses dedicated SDAIN (input) and SDAOUT (open-drain output) pins to simplify opto-isolation of the I²C bus in high-noise or high-voltage PoE systems. This separation eliminates level-shifting complexity and enables galvanic isolation using two optocouplers-one per direction-while maintaining full 1 MHz I²C functionality required for real-time port monitoring.
How does the LTC4274AIUHF-3#PBF ensure reliable detection in high-capacitance cabling environments?
The LTC4274AIUHF-3#PBF employs a proprietary 4-point detection mechanism combining 2-point forced voltage and 2-point forced current, with high-capacitance legacy device detection explicitly cited in its FEATURES list. This architecture rejects false triggers from long cables (>100m), bundled runs, or capacitive loads that would cause premature or missed detection in conventional 2-point schemes.
Can the LTC4274AIUHF-3#PBF be used in both endpoint and midspan PoE architectures?
Yes-the LTC4274AIUHF-3#PBF supports both configurations. The MID pin selects midspan mode (internally pulled down), while endpoint operation is default. Its datasheet lists applications including "LTPoE++ PSE Switches/Routers" (endpoint) and "LTPoE++ PSE Midspans", and the midspan backoff timer (2.5 s typ) is specifically engineered for reliable cascaded deployment in midspan topologies.
LTC4274AIUHF-3#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 38-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- Controller (PSE)
- Number of Channels:
- 1
- Power - Max:
- 70 W
- Internal Switch(s):
- No
- Auxiliary Sense:
- No
- Standards:
- 802.3at (PoE+), 802.3af (PoE), LTPoE++
- Voltage - Supply:
- 45V ~ 57V
- Current - Supply:
- 2.4mA
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 38-QFN (5x7)
LTC4274AIUHF-3#PBF FAQ
1.How can I place an order for LTC4274AIUHF-3#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC4274AIUHF-3#PBF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LTC4274AIUHF-3#PBF reliable?
The price and inventory of LTC4274AIUHF-3#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC4274AIUHF-3#PBF is usually 5 days.
3.What payment methods are accepted for LTC4274AIUHF-3#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC4274AIUHF-3#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC4274AIUHF-3#PBF?
LTC4274AIUHF-3#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC4274AIUHF-3#PBF order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LTC4274AIUHF-3#PBF?
For technical support, including LTC4274AIUHF-3#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC4274AIUHF-3#PBF requirements.
6.How does Aetrix verify that LTC4274AIUHF-3#PBF is sourced from the original manufacturer or authorized distributors?
All LTC4274AIUHF-3#PBF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LTC4274AIUHF-3#PBF meets industry standards.
7.What is the process for return or replacement of LTC4274AIUHF-3#PBF?
All LTC4274AIUHF-3#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC4274AIUHF-3#PBF, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LTC4274AIUHF-3#PBF part is unused and in its original packaging.
Return procedure for LTC4274AIUHF-3#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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