Overview
Features and Benefits
- Supports Self-Starting Secondary-Side Control
- Direct Flux Limit™ Guarantees No Saturation
- Active Clamp Drive with Delay Adjustment
- On-Chip Bridge Rectifier Eliminates Need for Separate Gate Drive Bias Supply
- Wide Input Supply Range: 8V and Up (Limited Only by External Components)
- Linear Regulator Controller for Fast Start-Up
- High Speed Gate Drivers
- Precision UVLO with Adjustable Hysteresis
- Overcurrent Protection
- Overtemperature Protection
- Adjustable Start-Up Frequency and Soft-Start
- Tiny 16-Lead MSOP Package
Product Details
The LTC3765 is a start-up controller and gate driver for use in a self-starting secondary-side control forward converter. When combined with the LTC3766 secondary-side synchronous forward controller, a complete isolated power supply is created using a minimum of discrete parts. A proprietary scheme is used to multiplex gate drive signals and bias power across the isolation barrier through a small pulse transformer. The LTC3765 contains an onchip bridge rectifier that extracts gate drive bias power from this pulse transformer, eliminating the need for a separate bias supply. A precision undervoltage lockout circuit and linear regulator controller ensure a quick and well-controlled start-up.
The LTC3765 includes an active clamp output for driving an external PMOS, as well as an adjustable delay to optimize efficiency. The active clamp architecture reduces voltage stress on the main power switch, and provides the highest possible efficiency. Overcurrent protection and the Direct Flux Limit guarantee no transformer saturation without compromising transient response.
Applications
- Isolated Battery Chargers
- Isolated 48V Telecommunication Systems
- Servers and Embedded Computing
- Automotive and Heavy Equipment
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (5)
Documentation
Reliability Data (1)
Tools & Simulations
LTspice
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, 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.
LTspice Simulations
Models for the following parts are available in LTspice:
Reference Materials
Product Selector Card (1)
Design a Simple, Efficient and Reliable Forward Converter
LTC3765/LTC3766 Video Product Brief
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Discussions
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Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
