How to build a simple and efficient isolated power supply below 2W

Asynchronous flyback topology is widely used in isolated power supplies, ranging from power levels below 1W to tens of W. As more “green mode” standards continue to emerge around the world, the requirements to improve light-load efficiency and reduce no-load input standby current are more stringent than ever. Unfortunately, traditional isolated power supplies using optocouplers are no longer able to achieve the required performance.
The new LT®8300 uses only 5 external components (input capacitor, output capacitor, transformer, feedback resistor and output diode) to build a 5V/300mA low IQ isolated power supply with 36V to 72V input. The simple LT8300 solution offers no compromise in performance, achieving 85% peak efficiency, less than 250µA no-load input standby current, ±1% output load and voltage regulation, and less than 50mV peak-to-peak output voltage ripple. wave, as well as good transient and startup performance. Watch the video to learn more.

• Chapter 1：How to build a simple and efficient isolated power supply below 2W (5 minutes and 40 seconds)