LTC3766 - High Efficiency, Secondary-Side Synchronous Forward Controller
Features
- Direct Flux Limit™ Guarantees No Saturation
- Fast and Accurate Average Current Limit
- Clean Start-Up Into Pre-Biased Output
- Secondary-Side Control for Fast Transient Response
- Simple, Self-Starting Architecture
- Synchronous MOSFET Reverse Current Limit
- PolyPhase® Operation Eases High-Power Design
- True Remote Sense Differential Amplifier
- Remote Sense Reverse Protection
- High Voltage Linear Regulator Controller
- Internal LDO Powers Gate Drive from VOUT
- Overtemperature/Overvoltage Protection
- Low Profile 4mm × 5mm QFN and Narrow 28-Lead SSOP Packages
Typical Application
Description
The LTC®3766 is a PolyPhase-capable secondary-side controller for synchronous forward converters. When used in conjunction with the LTC3765 active-clamp forward controller and gate driver, the part creates a complete isolated power supply that combines the power of multiphase operation with the speed of secondary-side control.
The LTC3766 has been designed to simplify the design of active clamp forward converters. Working in concert with the LTC3765, the LTC3766 forms a robust, self-starting converter that eliminates the need for the separate bias regulator that is commonly used in secondary-side control applications. A precision current-limit coupled with clean start-up into a pre-biased load make the LTC3766 an excellent choice for high-power battery charger applications.
The LTC3766 provides extensive remote sensing and output protection features, while Direct Flux Limit guarantees no transformer saturation without compromising transient response. A linear regulator controller and internal bypass LDO are also provided to simplify the generation of the secondary-side bias voltage.
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 |
|---|---|---|---|---|---|
| LTC3766EGN#PBF | SSOP-28 | GN | E | 05-08-1641 (GN28) | Yes |
| LTC3766EGN#TRPBF | SSOP-28 | GN | E | 05-08-1641 (GN28) | Yes |
| LTC3766EUFD#PBF | 4x5 QFN-28 | UFD | E | 05-08-1712 | Yes |
| LTC3766EUFD#TRPBF | 4x5 QFN-28 | UFD | E | 05-08-1712 | Yes |
| LTC3766HGN#PBF | SSOP-28 | GN | H | 05-08-1641 (GN28) | Yes |
| LTC3766HGN#TRPBF | SSOP-28 | GN | H | 05-08-1641 (GN28) | Yes |
| LTC3766HUFD#PBF | 4x5 QFN-28 | UFD | H | 05-08-1712 | Yes |
| LTC3766HUFD#TRPBF | 4x5 QFN-28 | UFD | H | 05-08-1712 | Yes |
| LTC3766IGN#PBF | SSOP-28 | GN | I | 05-08-1641 (GN28) | Yes |
| LTC3766IGN#TRPBF | SSOP-28 | GN | I | 05-08-1641 (GN28) | Yes |
| LTC3766IUFD#PBF | 4x5 QFN-28 | UFD | I | 05-08-1712 | Yes |
| LTC3766IUFD#TRPBF | 4x5 QFN-28 | UFD | I | 05-08-1712 | Yes |
| LTC3766MPGN#PBF | SSOP-28 | GN | MP | 05-08-1641 (GN28) | Yes |
| LTC3766MPGN#TRPBF | SSOP-28 | GN | MP | 05-08-1641 (GN28) | Yes |
| LTC3766MPUFD#PBF | 4x5 QFN-28 | UFD | MP | 05-08-1712 | Yes |
| LTC3766MPUFD#TRPBF | 4x5 QFN-28 | UFD | MP | 05-08-1712 | 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 | |
|---|---|---|---|---|---|---|
| LTC3766EGN#PBF | SSOP-28 | E | $5.54 | $3.88 | Yes | |
| LTC3766EGN#TRPBF | SSOP-28 | E | $3.94 | Yes | ||
| LTC3766EUFD#PBF | 4x5 QFN-28 | E | $5.54 | $3.88 | Yes | |
| LTC3766EUFD#TRPBF | 4x5 QFN-28 | E | $3.94 | Yes | ||
| LTC3766HGN#PBF | SSOP-28 | H | $6.54 | $4.58 | Yes | |
| LTC3766HGN#TRPBF | SSOP-28 | H | $4.64 | Yes | ||
| LTC3766HUFD#PBF | 4x5 QFN-28 | H | $6.54 | $4.58 | Yes | |
| LTC3766HUFD#TRPBF | 4x5 QFN-28 | H | $4.64 | Yes | ||
| LTC3766IGN#PBF | SSOP-28 | I | $6.11 | $4.28 | Yes | |
| LTC3766IGN#TRPBF | SSOP-28 | I | $4.34 | Yes | ||
| LTC3766IUFD#PBF | 4x5 QFN-28 | I | $6.11 | $4.28 | Yes | |
| LTC3766IUFD#TRPBF | 4x5 QFN-28 | I | $4.34 | Yes | ||
| LTC3766MPGN#PBF | SSOP-28 | MP | $16.51 | $11.56 | Yes | |
| LTC3766MPGN#TRPBF | SSOP-28 | MP | $11.62 | Yes | ||
| LTC3766MPUFD#PBF | 4x5 QFN-28 | MP | $16.51 | $11.56 | Yes | |
| LTC3766MPUFD#TRPBF | 4x5 QFN-28 | MP | $11.62 | 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 |
|---|---|---|---|
| DC1739A-B | LTC3765EMSE/LTC3766EGN Isolated Demo Board | Forward Converter, 18V ≤ VIN ≤ 72V; VOUT = 12V @ 12.5A | $300.00 | |
| DC1739B-C | LTC3765EMSE/LTC3766EGN Isolated Demo Board | Forward Converter, 9V ≤ VIN ≤ 36V; VOUT = 12V @ 10A | $300.00 | |
| DC2199A-A | LTC3765EMSE/LTC3766EGN Isolated Demo Board | Forward Converter, 36V ≤ VIN ≤ 60V; VOUT = 12V @ 30A | Contact Factory | |
| DC2199A-B | LTC3765EMSE/LTC3766EGN Isolated Demo Board | Forward Converter with Sync Rectification, 36V ≤ VIN ≤ 60V; VOUT = 24V @ 15A | Contact Factory | |
| DC2199B-C | LTC3765EMSE/LTC3766EGN Isolated Demo Board | Forward Converter with Sync Rectification, 36V ≤ VIN ≤ 60V; VOUT = 56V @ 5.4A | Contact Factory | |
| Buy Now | |||
Applications
- Isolated 48V Telecommunication Systems
- Isolated Battery Chargers
- Automotive and Military Systems
- Industrial, Avionics and Heavy Equipment
People Who Viewed This Product Also Viewed
- LTC3765 - Active Clamp Forward Controller and Gate Driver
- LT3758 - High Input Voltage, Boost, Flyback, SEPIC and Inverting Controller
- LT3748 - 100V Isolated Flyback Controller
- LT3798 - Isolated No Opto-Coupler Flyback Controller with Active PFC
- LT8705 - 80V VIN and VOUT Synchronous 4-Switch Buck- Boost DC/DC Controller
- LT4363 - High Voltage Surge Stopper with Current Limit
- LT3757 - Boost, Flyback, SEPIC and Inverting Controller
- LTC4364 - Surge Stopper with Ideal Diode
- LTC3722 - Synchronous Dual Mode Phase Modulated Full Bridge Controllers
- LT4320/LT4320-1 - Ideal Diode Bridge Controller
Product Notifications
Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.
Forgot your password? Click here.
Need help? Email mylinear@linear.com with questions and comments.
Design Tools
LTspice
LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice
To launch a ready to run LTspice demonstration circuit for this part:
- Step 1: If you have not installed LTspice on this computer, download and install LTspice
- Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
- LTC3765/LTC3766 Demo Circuit - Active Clamp Forward Converter (18-72V to 12V @ 12.5A)
- LTC3765/LTC3766 Demo Circuit - 120W Isolated Forward Converter with Synchronous Rectification (9-36V to 12V @ 10A)
- LTC3765/LTC3766 Demo Circuit - Active Clamp Forward Converter (36-60V to 12V @ 30A)
- LTC3765/LTC3766 Demo Circuit - Active Clamp Forward Converter (36-60V to 24V @ 15A)
- Step 3: If LTspice does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu
To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.
Models for the following parts are available in LTspice:
LTC3766
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.
