My Inquiry
My Account
Analog Devices Inc. LT4275BIMS#PBF
- Part No.:
- LT4275BIMS#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Power Over Ethernet (PoE) Controllers
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LT4275BIMS#PBF.pdf
- Description:
- IC POE CNTRL 1 CHANNEL 10MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:259
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT4275BIMS#PBF from Analog Devices (formerly Linear Technology) is an IEEE 802.3at-compliant Type 2 Powered Device (PD) controller for Power over Ethernet systems. It delivers up to 25.5W at the RJ45 connector, supports 100V absolute maximum input voltage, operates across –40°C to +85°C, and drives an external N-channel MOSFET via HSGATE/HSSRC for low-loss power switching in outdoor security cameras and industrial displays.
For engineers reviewing the LT4275BIMS#PBF datasheet, LT4275BIMS#PBF pinout, LT4275BIMS#PBF application, or LT4275BIMS#PBF equivalent, key selection considerations include its 25.5W PoE+ compliance, MSOP-10 package with exposed thermal pad, T2P open-drain PSE-type indicator, AUX-enabled auxiliary supply override down to 9V, and integrated signature resistor for IEEE 802.3af/at detection.
Technical Context
The LT4275BIMS#PBF implements IEEE 802.3at two-event physical layer classification using RCLASS to set 40mA class 4 current draw, and asserts T2P as a pulldown signal upon Type 2 PSE identification. Its internal charge pump enables N-channel MOSFET gate drive without requiring high-side level shifting.
It features programmable inrush control via external CGATE capacitor, undervoltage lockout thresholds of 27V/29V (turn-on/turn-off), and thermal protection that pulls down HSGATE and floats PWRGD above 150°C junction temperature. The AUX pin provides hysteresis-controlled auxiliary supply takeover with VAUXT = 6.3V threshold and IAUXH = 5.8µA sink current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Max Delivered Power | 25.5W - Complies with IEEE 802.3at Type 2 PD specification at the RJ45 port. |
| Input Voltage Range | 23V to 60V - Valid operating range at VPORT pin; supports standard PoE+ voltage envelope. |
| Absolute Max VPORT | 100V - Withstands transient surges and cable discharge events without damage. |
| Operating Temp Range | –40°C to +85°C - Qualified for commercial-temperature industrial and outdoor deployments. |
| Signature Resistance | 24.4kΩ ±0.7kΩ - Precision, temperature-compensated value meets IEEE 25kΩ detection requirement. |
| T2P Output Function | Open-drain pulldown - Indicates Type 2 PSE presence after PWRGD assertion; not connected in LT4275C. |
| AUX Threshold Voltage | 6.3V ±0.2V - Triggers auxiliary supply takeover; hysteresis provided by 5.8µA sink current. |
| Package Type | 10-Lead Plastic MSOP - Surface-mount, thermally enhanced package with GND-connected leadframe. |
Pinout & Package
LT4275BIMS#PBF uses a 10-lead plastic MSOP package (3mm × 3mm footprint) with GND-connected leadframe and no exposed pad. Thermal resistance θJC = 45°C/W. Pin 1 is marked by notch or dot; pin numbering follows standard MSOP convention (counterclockwise from notch).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IEEEUVLO (1) | Hot Swap UVLO Control | Grounding selects IEEE-compliant 27V/29V turn-on/turn-off thresholds; floating enables lower thresholds. |
| AUX (2) | Auxiliary Supply Sense | Sinks 5.8µA below 6.3V to enable hysteresis; asserts override mode when >6.3V, disconnecting signature and disabling classification. |
| RCLASS (3) | Classification Resistor Input | Accepts 34.8Ω to set 40mA class 4 current for IEEE 802.3at Type 2 operation; tolerance ≤1% required. |
| RCLASS++ (4) | LTPoE++ Classification Input | No-connect on LT4275BIMS#PBF - reserved for LT4275A; unconnected in B/C variants per datasheet. |
| GND (5) | Ground Reference | Main analog/digital ground; all internal references and protections referenced to this node. |
| T2P (6) | PSE Type Indicator | Open-drain output pulled low to indicate Type 2 PSE; invalid before PWRGD goes high. |
| PWRGD (7) | Power Good Signal | Open-drain output held low during classification/inrush; floats only in AUX override mode. |
| HSSRC (8) | MOSFET Source Reference | Connects to source of external N-channel MOSFET; defines return path for gate drive current. |
| HSGATE (9) | MOSFET Gate Driver | Charge-pump-driven output controlling external N-MOSFET gate; ramps linearly during inrush. |
| VPORT (10) | PD Input Power Rail | Primary high-voltage input (23–60V); connects to Ethernet transformer center tap and MOSFET drain. |
Key Features
| Feature | Design Value |
|---|---|
| N-channel MOSFET support | Eliminates need for costly P-channel FET; reduces conduction loss and board area via HSGATE/HSSRC interface. |
| Programmable inrush current | Set via external CGATE capacitor; enables precise IINRUSH ≈ 100mA compliance with IEEE 802.3at timing. |
| Integrated signature resistor | 24.4kΩ ±0.7kΩ trimmed resistor between VPORT–GND; eliminates external component and improves detection accuracy. |
| AUX-supply override | Enables seamless transition to 9–60V auxiliary input; disables PoE classification and isolates signature during takeover. |
| Thermal protection | Automatic HSGATE pull-down and PWRGD float above 150°C junction temperature; prevents latch-up during overload. |
| MSOP-10 package | Compact 3mm × 3mm footprint with standard lead pitch; compatible with automated SMT assembly and reflow profiles. |
Applications
| Outdoor Security Cameras | Commercial Information Displays |
|---|---|
|
Use Scenario: IP-based PTZ cameras deployed on building exteriors require reliable 25.5W PoE+ power and auxiliary fallback for extended runtime. IC Role / Device Role / Timing Role: LT4275BIMS#PBF acts as the primary PD interface controller, managing IEEE 802.3at classification, inrush limiting, and PSE-type signaling via T2P. Use Value: Enables single-cable deployment with guaranteed 25.5W delivery, thermal resilience to ambient extremes, and seamless AUX switchover during PoE interruption. |
Use Scenario: Large-format LCD kiosks in airports or retail spaces use PoE+ for simplified cabling and centralized UPS backup. IC Role / Device Role / Timing Role: LT4275BIMS#PBF controls hot-swap sequencing, provides PWRGD hold-off for isolated DC/DC startup, and signals PSE capability to system microcontroller via T2P. Use Value: Ensures clean power-up without inrush-induced brownouts, supports auxiliary 24VAC input for redundancy, and maintains IEEE 802.3at compliance across temperature range. |
| Industrial Ethernet Gateways | High-Temperature Wireless Access Points |
|
Use Scenario: DIN-rail mounted gateways in factory automation environments operate continuously at elevated ambient temperatures. IC Role / Device Role / Timing Role: LT4275BIMS#PBF serves as robust PD front-end with overtemperature shutdown, 100V surge tolerance, and stable signature under thermal stress. Use Value: Delivers uninterrupted 25.5W power while surviving junction temperatures up to 125°C ambient, reducing field failure risk in uncooled enclosures. |
Use Scenario: Outdoor Wi-Fi 6 access points mounted on cell towers require PoE+ power with auxiliary 12VDC backup for battery-backed operation. IC Role / Device Role / Timing Role: LT4275BIMS#PBF manages dual-input power arbitration, asserts T2P to confirm PoE+ availability to host MCU, and initiates graceful failover on AUX activation. Use Value: Guarantees continuous RF operation during PoE outages via sub-10ms AUX takeover, validated across –40°C to +85°C operating range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PoE+ powered device controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC4265 | Integrates 100V/1A internal MOSFET; no external FET required. Higher quiescent current (1.1mA vs 0.7mA). | Reduces BOM count and layout area but limits max current to 1A; less suitable for high-efficiency >20W designs needing ultra-low RDS(ON). | Select LTC4265 when board space is constrained and 1A FET current suffices; choose LT4275BIMS#PBF when optimizing for efficiency, thermal performance, or custom MOSFET selection. |
| MAX5984A | IEEE 802.3at-compliant PD controller with integrated 100V/0.8A MOSFET; supports 1-event classification only. | Lacks T2P PSE-type signaling and AUX override; no provision for auxiliary supply takeover or non-standard low-voltage PoE. | Choose MAX5984A for cost-sensitive, fixed-function PoE+ endpoints without auxiliary input or PSE negotiation needs; LT4275BIMS#PBF preferred for feature-rich, field-deployable systems. |
Compared with LTC4265 and MAX5984A, the LT4275BIMS#PBF offers superior thermal management via external N-MOSFET selection, full IEEE 802.3at two-event classification with T2P feedback, and robust AUX-supported power redundancy-making it optimal for industrial and outdoor PoE+ applications demanding reliability and flexibility.
Availability
LT4275BIMS#PBF is available at Aetrix Electronics and suitable for outdoor security camera equipment, commercial information displays, and industrial Ethernet gateways requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LT4275BIMS#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 acquired Linear Technology in 2017 and maintains its legacy portfolio of high-performance analog ICs for power, signal conditioning, and interface applications.
The LT4275 family belongs to Linear's Power over Ethernet (PoE) interface product line, designed specifically for IEEE 802.3af/at and LTPoE++ powered devices requiring robust, high-efficiency, and thermally resilient PD controllers.
FAQ
What is the maximum power delivered by the LT4275BIMS#PBF?
The LT4275BIMS#PBF is an IEEE 802.3at-compliant Type 2 Powered Device controller delivering up to 25.5W at the RJ45 connector. This rating is confirmed in the datasheet's "Order Information" table and "Applications" section, and applies specifically to the LT4275B grade-not the A or C variants. The LT4275BIMS#PBF does not support LTPoE++ or 802.3af-only modes beyond its defined 25.5W capability.
Does the LT4275BIMS#PBF support auxiliary power supply override?
Yes, the LT4275BIMS#PBF supports auxiliary power override via the AUX pin. When AUX voltage exceeds 6.3V (VAUXT), the device disconnects the signature resistor, disables classification, pulls down HSGATE, and floats PWRGD-enabling seamless takeover by an external 9–60V auxiliary source. This behavior is explicitly documented in the "Auxiliary Supply Override" section and verified in the Electrical Characteristics table (VAUXT = 6.3V, IAUXH = 5.8µA).
What package type and thermal characteristics does the LT4275BIMS#PBF have?
The LT4275BIMS#PBF uses a 10-lead plastic MSOP package (3mm × 3mm) with θJC = 45°C/W. Unlike the DFN variant, the MSOP version has no exposed pad; thermal dissipation relies on PCB copper and leadframe conduction. The datasheet specifies TJMAX = 150°C and confirms operation from –40°C to +85°C ambient, with thermal protection activating above junction temperature threshold.
Is the T2P pin functional on the LT4275BIMS#PBF?
Yes, the T2P pin is fully functional on the LT4275BIMS#PBF. As stated in the "Pin Functions" section and "Order Information" table, T2P is an open-drain output used exclusively on LT4275A and LT4275B variants to indicate Type 2 PSE presence by pulling low after PWRGD becomes valid. It is explicitly marked "not connected" only on LT4275C, confirming T2P's active role in LT4275BIMS#PBF operation.
What is the purpose of the RCLASS++ pin on the LT4275BIMS#PBF?
The RCLASS++ pin is not connected on the LT4275BIMS#PBF. Per the "Pin Functions" section and "Order Information" table footnote, RCLASS++ is reserved for LTPoE++ classification in the LT4275A variant only and is unconnected (NC) in LT4275B and LT4275C versions. No external component should be attached to pin 4 of the LT4275BIMS#PBF, and its state has no effect on IEEE 802.3at operation.
LT4275BIMS#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- Controller (PD)
- Number of Channels:
- 1
- Power - Max:
- 25.5 W
- Internal Switch(s):
- No
- Auxiliary Sense:
- Yes
- Standards:
- 802.3at (PoE+), 802.3af (PoE)
- Voltage - Supply:
- 23V ~ 60V
- Current - Supply:
- 2mA (Max)
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-MSOP
LT4275BIMS#PBF FAQ
1.How can I place an order for LT4275BIMS#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT4275BIMS#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 LT4275BIMS#PBF reliable?
The price and inventory of LT4275BIMS#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT4275BIMS#PBF is usually 5 days.
3.What payment methods are accepted for LT4275BIMS#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT4275BIMS#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT4275BIMS#PBF?
LT4275BIMS#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT4275BIMS#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 LT4275BIMS#PBF?
For technical support, including LT4275BIMS#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT4275BIMS#PBF requirements.
6.How does Aetrix verify that LT4275BIMS#PBF is sourced from the original manufacturer or authorized distributors?
All LT4275BIMS#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 LT4275BIMS#PBF meets industry standards.
7.What is the process for return or replacement of LT4275BIMS#PBF?
All LT4275BIMS#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT4275BIMS#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 LT4275BIMS#PBF part is unused and in its original packaging.
Return procedure for LT4275BIMS#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT4275BIMS#PBF Tags
-
TPS2378DDAR
Texas Instruments
-
TPS23753APWR
Texas Instruments
-
TPS23756PWPR
Texas Instruments
-
TPS23750PWPR
Texas Instruments
-
MP8007GV-Z
Monolithic Power Systems Inc.
-
TPS23861PWR
Texas Instruments
-
TPS23753PWR
Texas Instruments
-
PD69201ILD-TR
Microchip Technology
-
SI3402-B-GM
Skyworks Solutions Inc.
-
SI3402-B-GMR
Skyworks Solutions Inc.
-
SI34071-A01-GMR
Skyworks Solutions Inc.
-
SI3404-A-GMR
Skyworks Solutions Inc.
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
