LTC4270/LTC4271 - 12-Port PoE/PoE+/LTPoE++ PSE Controller
Features
- 12 Independent PSE Channels
- Compliant with IEEE 802.3at Type 1 and 2
- Chipset Provides Electrical Isolation
Reduced BOM Cost
Eliminates up to 6 High Speed Opto-Couplers
Eliminates Isolated 3.3V Power Supply - Low Power Dissipation
0.25Ω Sense Resistance Per Channel - Very High Reliability 4-Point PD Detection
2-Point Forced Voltage
2-Point Forced Current - VEE and VPORT Monitoring
- 1 Second Rolling IPORT Averaging
- Supports 2-Pair and 4-Pair Output Power
- 1MHz I2C Compatible Serial Control Interface
- Available In Three Power Grades
A-Grade – LTPoE++™ 38.7W to 90W
B-Grade – PoE+ 25.5W
C-Grade – PoE 13W - Available In 52-Lead 7mm × 8mm (LTC4270) and 24-Lead 4mm × 4mm (LTC4271) QFN Packages
Typical Application
Description
The LTC®4270/LTC4271 chipset is a 12-port power sourcing equipment (PSE) controller designed for use in IEEE 802.3at Type 1 and Type 2 (high power) compliant Power over Ethernet (PoE) systems. Transformer-isolated communication protocol replaces expensive opto-couplers and complex isolated 3.3V supply resulting in significant BOM cost savings. The LTC4270/LTC4271 chipset delivers lowest-in-industry heat dissipation by utilizing low-RDS(ON) external MOSFETs and 0.25Ω sense resistors.
Advanced power management features include per-port 12- bit current monitoring ADCs, DAC-programmable current limit, and versatile fast shut-down of preselected ports. Advanced power management host software is available under a no-cost license. PD discovery uses a proprietary dual-mode 4-point detection mechanism ensuring excellent immunity from false PD detection. Midspan PSEs are supported with 2-event classification and a 2 second backoff timer. The LTC4270/LTC4271 includes an I2C serial interface operable up to 1MHz.
The LTC4270/LTC4271 is available in multiple power grades allowing delivered PD power up to 90W.
Packaging
For complete and up to date package information and drawings, please refer to our packaging page
QFN-52, QFN-24
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 |
|---|---|---|---|---|---|---|
| LTC4270AIUKG#PBF | QFN | 52 | I | $14.71 | $10.30 | View |
| LTC4270AIUKG#TRPBF | QFN | 52 | I | $10.36 | View | |
| LTC4270BIUKG#PBF | QFN | 52 | I | $12.86 | $9.00 | View |
| LTC4270BIUKG#TRPBF | QFN | 52 | I | $9.06 | View | |
| LTC4270CIUKG#PBF | QFN | 52 | I | $12.86 | $9.00 | View |
| LTC4270CIUKG#TRPBF | QFN | 52 | I | $9.06 | 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 |
|---|---|---|---|
| DC1840A | LTC4270B/LTC4271: (DC1680 + DC1682) 12-Port 25.5W Demo Kit (req DC590) | $300.00 | |
| Buy Now | |||
Companion Boards
| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC590B | USB Serial Controller for Linear Technology QuikEval Demo Boards | $50.00 | |
| Buy Now | |||
Applications
- PoE PSE Switches/Routers
- PoE 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.