Power Management
Power-Over-Ethernet (PoE) Interface Controllers
Powered Device (PD)
Space & Harsh Environment
Extended Temperature Plastic (H & MP)
Extended Temperature (H & MP) Power Management
LT4275 - LTPoE++/PoE+/PoE PD Controller
Features
- IEEE 802.3af/at and LTPoE++™ Powered Device (PD) Controller
- LTPoE++ Supports Power Levels Up to 90W
- LT4275A Supports All of the Following Standards:
LTPoE++ 38.7W, 52.7W, 70W and 90W
IEEE 802.3at 25.5W Compliant
IEEE 802.3af Up to 13W Compliant - LT4275B is IEEE 802.3at/af Compliant
- LT4275C is IEEE 802.3af Compliant
- 100V 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 9V
- Optional Support of Non-Standard Low Voltage PoE
- Available in 10-Lead MSOP and 3mm × 3mm DFN Packages
Typical Application
Description
The LT®4275 is a pin-for-pin compatible family of IEEE 802.3 and LTPoE++ powered device (PD) controllers.
The LT4275A employs a proprietary LTPoE++ classification scheme, delivering 38.7W, 52.7W, 70W or 90W 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 25.5W. The LT4275C is an IEEE 802.3af compliant, Type 1 (PoE) PD delivering up to 13W.
The LT4275 internal charge pump provides an N-channel MOSFET solution, eliminating a larger and more costly 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 opto-coupler 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 LT4275A can be configured to support all possible LTPoE++, 802.3at and 802.3af power levels with external component changes.
Packaging
For complete and up to date package information and drawings, please refer to our packaging page
MS-10, DFN-10
Order Info
- Part numbers ending in PBF are lead free. Please contact LTC marketing for information on lead based finish parts.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) | Price (1k)* | RoHS Data |
|---|---|---|---|---|---|---|
| LT4275AHDD#PBF | DFN | 10 | H | $3.86 | $2.70 | View |
| LT4275AHDD#TRPBF | DFN | 10 | H | $2.76 | View | |
| LT4275AHMS#PBF | MSOP | 10 | H | $3.86 | $2.70 | View |
| LT4275AHMS#TRPBF | MSOP | 10 | H | $2.76 | View | |
| LT4275AIDD#PBF | DFN | 10 | I | $3.21 | $2.25 | View |
| LT4275AIDD#TRPBF | DFN | 10 | I | $2.31 | View | |
| LT4275AIMS#PBF | MSOP | 10 | I | $3.21 | $2.25 | View |
| LT4275AIMS#TRPBF | MSOP | 10 | I | $2.31 | View | |
| LT4275BHDD#PBF | DFN | 10 | H | $3.09 | $2.16 | View |
| LT4275BHDD#TRPBF | DFN | 10 | H | $2.22 | View | |
| LT4275BHMS#PBF | MSOP | 10 | H | $3.09 | $2.16 | View |
| LT4275BHMS#TRPBF | MSOP | 10 | H | $2.22 | View | |
| LT4275BIDD#PBF | DFN | 10 | I | $2.57 | $1.80 | View |
| LT4275BIDD#TRPBF | DFN | 10 | I | $1.86 | View | |
| LT4275BIMS#PBF | MSOP | 10 | I | $2.57 | $1.80 | View |
| LT4275BIMS#TRPBF | MSOP | 10 | I | $1.86 | View | |
| LT4275CHDD#PBF | DFN | 10 | H | $2.49 | $1.74 | View |
| LT4275CHDD#TRPBF | DFN | 10 | H | $1.80 | View | |
| LT4275CHMS#PBF | MSOP | 10 | H | $2.49 | $1.74 | View |
| LT4275CHMS#TRPBF | MSOP | 10 | H | $1.80 | View | |
| LT4275CIDD#PBF | DFN | 10 | I | $2.07 | $1.45 | View |
| LT4275CIDD#TRPBF | DFN | 10 | I | $1.51 | View | |
| LT4275CIMS#PBF | MSOP | 10 | I | $2.07 | $1.45 | View |
| LT4275CIMS#TRPBF | MSOP | 10 | I | $1.51 | View | |
| Buy Now • Request Samples | ||||||
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 |
|---|---|---|---|
| DC1788A-A | LT4275A (38.7W-90W) | OBSOLETE USE DC1788B-A | Contact Factory | |
| DC1788A-B | LT4275B (25.5W) PoE+ PD Controller | $75.00 | |
| DC1788A-C | LT4275C (13W) PoE PD Controller | $75.00 | |
| DC1788B-A | LT4275A (38.7W-90W) LTPoE++ PD Controller (req. DC1814 or DC1815) | $75.00 | |
| DC1788B-B | LT4275B (25.5W) PoE+ PD Controller | Contact Factory | |
| DC1788B-C | LT4275C (13W) PoE PD Controller | Contact Factory | |
| Buy Now | |||
Companion Boards
| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1814A-A | LTC4274A-1: LTPoE++ (38.7W) PSE (req. DC1788) | $100.00 | |
| DC1814A-B | LTC4274A-2: LTPoE++ (52.7W) PSE (req. DC1788) | $100.00 | |
| DC1814A-C | LTC4274A-3: LTPoE++ (70W) PSE (req. DC1788) | $100.00 | |
| DC1814A-D | LTC4274A-4: LTPoE++ (90W) PSE (req. DC1788) | $100.00 | |
| DC1815A-A | LTC4266A-1: 4-Port 38.7W LTPoE++ Midspan PSE (req. DC1788 & DC590) | $200.00 | |
| DC1815A-B | LTC4266A-2: 4-Port 52.7W LTPoE++ Midspan PSE (req. DC1788 & DC590) | $200.00 | |
| DC1815A-C | LTC4266A-3 4-Port 70W LTPoE++ Midspan PSE (req. DC1788 & DC590) | $200.00 | |
| DC1815A-D | LTC4266A-4: 4-Port 90W LTPoE++ Midspan PSE (req. DC1788 & DC590) | $200.00 | |
| Buy Now | |||
Applications
- High Power Wireless Data Systems
- Outdoor Security Camera Equipment
- Commercial and Public Information Displays
- High Temperature Industrial Applications
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Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.