LTC4274A/LTC4274C - Single PoE/PoE+/LTPoE++ PSE Controller
Features
- Compliant with IEEE 802.3at Type 1 and 2
- Low Power Dissipation
0.25Ω Sense Resistance Per Channel - Very High Reliability 4-Point PD Detection
2-Point Forced Voltage
2-Point Forced Current - High Capacitance Legacy Device Detection
- 1MHz I2C Compatible Serial Control Interface
- Midspan Backoff Timer
- Supports 2-Pair and 4-Pair Output Power
- Available in Multiple Power Grades
LTC4274A-1: LTPoE++™ 38.7W
LTC4274A-2: LTPoE++ 52.7W
LTC4274A-3: LTPoE++ 70W
LTC4274A-4: LTPoE++ 90W
LTC4274C: PoE 13W - Available in 38-Pin 5mm × 7mm QFN Package
Typical Application
Description
The LTC®4274A is a single Power Sourcing Equipment (PSE) controller capable of delivering up to 90W of LTPoE++ power to a compatible LTPoE++ Powered Device (PD). A proprietary detection/classification scheme allows mutual identification between a LTPoE++ PSE and LTPoE++ PD while remaining compatible and interoperable with existing Type 1 (13W) and Type 2 (25.5W) PDs. The LTC4274A feature set is a superset of the popular LTC4274. These PSE controllers feature low-RON external MOSFETs and 0.25Ω sense resistors which are especially important at the LTPoE++ current levels to maintain the lowest possible heat dissipation.
The LTC4274C targets fully automatic PSE systems powering Type 1 (up to 13W) PDs.
Advanced power management features include: a 14-bit current monitoring ADC, DAC-programmable current limit, and versatile quick port shutdown. PD Discovery uses a proprietary dual-mode 4-point detection mechanism ensuring excellent immunity from false PD detection. The LTC4274A/LTC4274C includes an I2C serial interface operable up to 1MHz.
The LTC4274A/LTC4274C is available in multiple power grades, allowing delivered PD power of 13W, 25.5W, 38.7W, 52.7W, 70W and 90W. These controllers are available in a 38-pin 5mm × 7mm QFN package.
Packaging
For complete and up to date package information and drawings, please refer to our packaging page
QFN-38
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 |
|---|---|---|---|---|---|---|
| LTC4274AIUHF-1#PBF | QFN | 38 | I | $7.71 | $5.40 | View |
| LTC4274AIUHF-1#TRPBF | QFN | 38 | I | $5.46 | View | |
| LTC4274AIUHF-2#PBF | QFN | 38 | I | $7.71 | $5.40 | View |
| LTC4274AIUHF-2#TRPBF | QFN | 38 | I | $5.46 | View | |
| LTC4274AIUHF-3#PBF | QFN | 38 | I | $7.71 | $5.40 | View |
| LTC4274AIUHF-3#TRPBF | QFN | 38 | I | $5.46 | View | |
| LTC4274AIUHF-4#PBF | QFN | 38 | I | $7.71 | $5.40 | View |
| LTC4274AIUHF-4#TRPBF | QFN | 38 | I | $5.46 | View | |
| LTC4274CIUHF#PBF | QFN | 38 | I | $6.43 | $4.50 | View |
| LTC4274CIUHF#TRPBF | QFN | 38 | I | $4.56 | View | |
| LTC4274CUHF#PBF | QFN | 38 | C | $6.43 | $4.50 | View |
| LTC4274CUHF#TRPBF | QFN | 38 | C | $4.56 | View | |
| LTC4274IUHF#PBF | QFN | 38 | I | $7.07 | $4.95 | View |
| LTC4274IUHF#TRPBF | QFN | 38 | I | $5.01 | 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 |
|---|---|---|---|
| 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 | |
| Buy Now | |||
Companion Boards
| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1788A-A | LT4275A (38.7W-90W) | OBSOLETE USE DC1788B-A | Contact Factory | |
| Buy Now | |||
Applications
- LTPoE++ PSE Switches/Routers
- LTPoE++ PSE Midspans
- IEEE 802.3at Type 1 PSE Switches/Routers
- IEEE 802.3at Type 1 PSE Midspans
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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.