LT3825
Linear Technology
Demonstration circuit 1143 is a 20 Watt Isolated Flyback Converter with Synchronous Rectification and Primary-Side Regulation featuring the LT3825.
Design DocumentAnalog
LT3825 Demonstration Circuit 1143: 20W Isolated Flyback Converter
20W isolated flyback converter using the LT3825 with synchronous rectification. Delivers 3.3V at 6A from a 36V-72V input with primary-side regulation and 88% efficiency.
Overview
Demonstration circuit 1143 features the LT3825, a synchronous flyback PWM controller designed for 20W isolated power supplies. The circuit converts an input voltage range of 36V to 72V into a regulated 3.3V output at up to 6A. It utilizes primary-side regulation by sensing the housekeeping winding voltage, which eliminates the need for an opto-isolator. The design achieves over 88% efficiency through synchronous rectification and operates at a 250kHz switching frequency. Key specifications include 1500VDC isolation, undervoltage lockout, and 'burp-mode' short-circuit protection. The footprint area is 1.0 inch square.
Use Cases
- Telecom power systems
- Isolated DC/DC conversion
- Industrial control power supplies
- 48V distributed power architectures
Topics
LT3825
Flyback Converter
Synchronous Rectification
Primary-Side Regulation
DC1143A
Isolated Power Supply
Telecom Power
20W DC/DC
3.3V Output
Referenced Parts
| LT3825 | Linear Technology | Demonstration circuit 1143 is a 20 Watt Isolated Flyback Converter with Synchronous Rectification and Primary-Side Regulation featuring the LT3825. |