LTC4268-1 - High Power PD with Synchronous NoOpto Flyback Controller
Features
- Robust 35W PD Front End
- IEEE 802.3af Compliant
- Rugged 750mA Power MOSFET with Precision Dual Level Current Limit
- High Performance Synchronous Flyback Controller
- IEEE Isolation Obtained Without an Optoisolator
- Adjustable Frequency from 50kHz to 250kHz
- Tight Multi-Output Regulation with Load Compensation
- Onboard 25k Signature Resistor
- Programmable Classification Current to 75mA
- Complete Thermal and Over-Current Protection
- Available in Compact 32-Pin 7mm x 4mm DFN Package
Typical Application
Description
The LTC4268-1 is an integrated Powered Device (PD) controller and switching regulator intended for IEEE 802.3af and high power PoE applications up to 35W. By including a precision dual current limit, the LTC4268-1 keeps inrush below IEEE 802.3af current limit levels to ensure interoperability success while enabling high power applications with a 750mA operational current limit.
The LTC4268-1 synchronous, current-mode, flyback controller generates multiple supply rails in a single conversion providing for the highest system efficiency while maintaining tight regulation across all outputs. The LTC4268-1 includes Linear Technology’s patented NoOpto feedback topology to provide full IEEE 802.3af isolation without the need of optoisolator circuitry.
The oversized power path and high performance flyback controller of the LTC4268-1 combine to make the ultimate solution for power hungry PoE applications such as WAPs, PTZ security cameras, RFID readers and ultra-efficient 802.3af applications running near the 12.95W limit.
The LTC4268-1 is available in a space saving 32-pin DFN package.
Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LTC4268CDKD-1#PBF | 7x4 DFN-32 | DKD | C | 05-08-1734 | Yes |
| LTC4268CDKD-1#TRPBF | 7x4 DFN-32 | DKD | C | 05-08-1734 | Yes |
| LTC4268IDKD-1#PBF | 7x4 DFN-32 | DKD | I | 05-08-1734 | Yes |
| LTC4268IDKD-1#TRPBF | 7x4 DFN-32 | DKD | I | 05-08-1734 | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- 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 | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC4268CDKD-1#PBF | 7x4 DFN-32 | C | $3.43 | $2.40 | Yes | |
| LTC4268CDKD-1#TRPBF | 7x4 DFN-32 | C | $3.43 | $2.46 | Yes | |
| LTC4268IDKD-1#PBF | 7x4 DFN-32 | I | $4.11 | $2.88 | Yes | |
| LTC4268IDKD-1#TRPBF | 7x4 DFN-32 | I | $4.11 | $2.94 | Yes | |
| 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 |
|---|---|---|---|
| DC1080A | LTC4268 High Power PD with Synchronous NoOpto Flyback Controller | $75.00 | |
| Buy Now | |||
Applications
- VoIP Phones with Advanced Display Options
- Dual-Radio Wireless Access Points
- PTZ Security Cameras
- RFID Readers
- Industrial Controls
- Magnetic Card Readers
- High Power PoE Systems
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Design Tools
Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:
- LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
- LTpowerCAD - A complete power supply selection, synthesis and design tool
- LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
- PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
- Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
- LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
- And More!
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.
