LT4275/LT4276 LTPoE++™ Controllers

Analog Devices’ PoE controllers for information displays, security, and wireless data systems

Image of Analog Devices' LT4275/LT4276 LTPoE++ ControllersAnalog Devices' LT4275 and LT4276 are IEEE 802.3 and LTPoE++ powered device (PD) controllers. The LT4275A employs a proprietary LTPoE++ classification scheme, delivering 38.7 W, 52.7 W, 70 W, or 90 W of power at the PD RJ45 connector. The LT4275A is fully compatible with IEEE 802.3. The LT4275B is an IEEE 802.3at compliant, type 2 (PoE+) PD delivering up to 25.5 W. The LT4275C is an IEEE 802.3af compliant, type 1 (PoE) PD delivering up to 13 W.

The LT4275 internal charge pump provides an N-channel MOSFET solution, eliminating a larger and costlier P-channel MOSFET. A low RDS(ON) MOSFET also maximizes power delivery and efficiency, reduces power and heat dissipation, and eases thermal design. Startup inrush current is adjustable with an external capacitor. The LT4275 also includes a power good output, on-board signature resistor, undervoltage lockout, and thermal protection. The LT4275A/LT4275B drives a single optocoupler to indicate the power level of the attached PSE. Pin-selectable support for non-standard low voltage operation is provided. Auxiliary power override is supported with the AUX pin.

The LT4276 includes an isolated switching regulator controller capable of synchronous operation in both forward and flyback topologies with auxiliary power support. The LT4276A employs the LTPoE++ classification scheme, receiving 38.7 W, 52.7 W, 70 W, or 90 W of power at the PD RJ45 connector, and is backward compatible with IEEE 802.3. The LT4276B is a fully 802.3at compliant, 25.5 W type 2 (PoE+) PD. The LT4276C is a fully 802.3af compliant, 13 W type 1 (PoE) PD. The LT4276 supports both forward and flyback power supply topologies, configurable for a wide range of PoE applications. The flyback topology supports no-opto feedback. Auxiliary input voltage can be accurately sensed with just a resistor divider connected to the AUX pin. The LT4276 utilizes an external, low RDS(ON) N-channel MOSFET for the Hot Swap function, maximizing power delivery and efficiency, reducing heat dissipation, and easing the thermal design. The LT4275 and LT4276 are ideal for information displays, security, and wireless data systems.

Image of Analog Devices' LT4275/LT4276 LTPoE++ Controllers
Image of Analog Devices' LT4275/LT4276 LTPoE++ Controllers
LT4275 Features LT4276 Features
  • IEEE 802.3af/at and LTPoE++ PD controller
  • LTPoE++ supports power levels up to 90 W
  • LT4275A supports all the following standards:
    • LTPoE++ 38.7 W, 52.7 W, 70 W, and 90 W
    • IEEE 802.3at 25.5 W compliant
    • IEEE 802.3af up to 13 W compliant
  • LT4275B is IEEE 802.3at/af compliant
  • LT4275C is IEEE 802.3af compliant
  • 100 V absolute maximum input voltage
  • Wide junction temperature range (-40°C to +125°C)
  • Overtemperature protection
  • Integrated signature resistor
  • External Hot Swap N-channel MOSFET for lowest power dissipation and highest system efficiency
  • Programmable aux power support as low as 9 V
  • Optional support of non-standard low voltage PoE
 
  •  IEEE802.3af/at and LTPoE++ 90 W PD with forward/flyback controller
  • LT4276A supports all the following standards:
    • LTPoE++ 38.7 W, 52.7 W, 70 W, and 90 W
    • IEEE 802.3at 25.5 W compliant
    • IEEE 802.3af up to 13 W compliant
  • LT4276B is IEEE 802.3at/af compliant
  • LT4276C is IEEE 802.3af compliant
  • Superior surge protection (100 V absolute maximum)
  • Wide junction temperature range (-40°C to +125°C)
  • Auxiliary power support as low as 9 V
  • No optoisolator required for flyback operation
  • External Hot Swap N-channel MOSFET for lowest power dissipation and highest system efficiency
  • >94% end-to-end efficiency with LT4321 ideal bridge
 Applications    
  • Commercial and public information displays
  • Outdoor security camera equipment
 
  • High-power wireless data systems
  • High-temperature industrial applications

LT4275 LTPoE++™ Controllers

ImageManufacturer Part NumberDescriptionAvailable QuantityView Details
EVAL BOARD FOR LT4275 90WDC1788B-AEVAL BOARD FOR LT4275 90W0View Details
DEV BOARD FOR LT4275A/LT4321DC2093A-ADEV BOARD FOR LT4275A/LT432147 - ImmediateView Details
DEV BOARD FOR LT4275B/LT4321DC2093A-BDEV BOARD FOR LT4275B/LT43210View Details
DEV BOARD FOR LT4275C/LT4321DC2093A-CDEV BOARD FOR LT4275C/LT43210View Details
DEMO BOARD LT4275/LT4321/LTM8027DC2125ADEMO BOARD LT4275/LT4321/LTM80278 - ImmediateView Details
8-PORT IO-LINK MASTER REF DESIGNDC2228A8-PORT IO-LINK MASTER REF DESIGN2 - ImmediateView Details

LT4276 LTPoE++™ Controllers

ImageManufacturer Part NumberDescriptionAvailable QuantityView Details
DEV BOARD FOR LT4276B/LT4321DC2046A-ADEV BOARD FOR LT4276B/LT43210View Details
DEV BOARD FOR LT4276B/LT4321DC2046A-BDEV BOARD FOR LT4276B/LT43211 - ImmediateView Details
DEV BOARD FOR LT4276B/LT4321DC2046A-CDEV BOARD FOR LT4276B/LT43213 - ImmediateView Details
DEV BOARD FOR LT4276B/LT4321DC2046A-DDEV BOARD FOR LT4276B/LT43211 - ImmediateView Details
DEV BOARD FOR LT4276A/LT4321DC2046A-EDEV BOARD FOR LT4276A/LT43210View Details
DEV BOARD FOR LT4276C/LT4321DC2046A-FDEV BOARD FOR LT4276C/LT43214 - ImmediateView Details
DEMO BOARD FOR LT4276B/LT4321DC2047A-ADEMO BOARD FOR LT4276B/LT43212 - ImmediateView Details
LT4276A/LT4321 DEMO BOARD LTPOE+DC2262A-ALT4276A/LT4321 DEMO BOARD LTPOE+0View Details
LT4276A/LT4321 DEMO BOARD LTPOE+DC2262A-BLT4276A/LT4321 DEMO BOARD LTPOE+4 - ImmediateView Details

LT4275 ICs

ImageManufacturer Part NumberDescriptionAvailable QuantityView Details
IC POE CNTRL 1 CHANNEL 10DFNLT4275AHDD#PBFIC POE CNTRL 1 CHANNEL 10DFN303 - ImmediateView Details
IC POE CNTRL 1 CHANNEL 10MSOPLT4275AHMS#PBFIC POE CNTRL 1 CHANNEL 10MSOP453 - ImmediateView Details
IC POE CNTRL 1 CHANNEL 10MSOPLT4275AHMS#TRPBFIC POE CNTRL 1 CHANNEL 10MSOP0View Details

LT4276 ICs

ImageManufacturer Part NumberDescriptionAvailable QuantityView Details
IC POE CNTRL 1 CHANNEL 28QFNLT4276AHUFD#PBFIC POE CNTRL 1 CHANNEL 28QFN0View Details
IC POE CNTRL 1 CHANNEL 28QFNLT4276AIUFD#PBFIC POE CNTRL 1 CHANNEL 28QFN0View Details
IC POE CNTRL 1 CHANNEL 28QFNLT4276BHUFD#PBFIC POE CNTRL 1 CHANNEL 28QFN0View Details
IC POE CNTRL 1 CHANNEL 28QFNLT4276BHUFD#TRPBFIC POE CNTRL 1 CHANNEL 28QFN0View Details
IC POE CNTRL 1 CHANNEL 28QFNLT4276BIUFD#PBFIC POE CNTRL 1 CHANNEL 28QFN0View Details
IC POE CNTRL 1 CHANNEL 28QFNLT4276CHUFD#PBFIC POE CNTRL 1 CHANNEL 28QFN0View Details
IC POE CNTRL 1 CHANNEL 28QFNLT4276CHUFD#TRPBFIC POE CNTRL 1 CHANNEL 28QFN0View Details
IC POE CNTRL 1 CHANNEL 28QFNLT4276CIUFD#PBFIC POE CNTRL 1 CHANNEL 28QFN0View Details
Published: 2018-08-06